Quick SEO for Drupal?

I agree with DeeZone.

Drupal is as SEO friendly as you want it to be. It is no more or less SEO capable as Wordpress.

Perhaps spend some time with it and you will understand.

I do recommend you take a look at some modules:

Meta Tags
Page Title
PathAuto
Path Redirect
Global Redirect
Path Logic

Wordpress is a fantastic tool at a few things. Drupal is fantastic at many things including those things that WP is great at. It is not the best tool for every project but as you peel back the layers you will be consistently amazed at what it can do.

Try this basic Drupal SEO tutorial.

IMHO, Drupal is better for SEO than WordPress because you have more control over URLs as well as site structure (Views). Drupal is worse than WP for SEO in only one way: paginated pages.

Drupal's SEO isn't terrible out of the box as long as you are using clean URLs and setup robots.txt correctly. A buggy robots.txt is the main out-of-the-box SEO problem that Drupal has.

Start with SEO Checklist
http://drupal.org/project/seo_checklist

Also, while I agree with others here that Drupal has the potential to be hella SEO, I completely understand your perception. Out of the box, it is not up to par w/ Wordpress. (I feel like people are being a little defensive on this thread. It's an occupational hazard of working with Drupal, which is fortunately less and less warranted all the time.) With minor configuration, though, Drupal handily surpasses Wordpress et al.

Here are the main config changes in the order I would apprach them:

1. Clean URLs. This is default in Drupal 6, so it almost goes without saying.
2. Path Redirect. Functionally equivalent to adding redirects to your .htaccess, but ties in with Pathauto and other tools. Lets you define short phrases that you can publish without having to create actual pages corresponding to them. (Which is great for print collateral.)
3. Global Redirect. Redirects all your "node/123" paths to the URL alias from [1]
4. Page Title. Lets you stipulate a different page title for each node. Can tie in with Pathauto.
5. Nodewords, which is the meta-tag manager. It can generate descriptions, abstracts and keyword lists automatically, or let you over-ride them. Also supports many other meta tags -- even Dublin Core.
6. SEO Checklist. It will guide you through a lot of things that will be very helpful. Not everything it tells you is strictly "right", but none of it will hurt you.
7. Google Analytics. You don't technically need the module to integrate GA with Drupal, but it gives you options that help you keep admin traffic out of your GA reporting. Also, you can integrate internal search with GA -- I haven't done it, so I'm not sure what the value is. I think you'd probably want to be fairly high-traffic before you bothered with it.
8. Pathauto. It takes a little bit of thinking to really grok how powerful it is -- and in fact you might not get that unless you use multiple content types. But using multiple content types, it can let you create some reasonably sophisticated path masks. (Don't bother configuring Pathauto until after you install Path Redirect, Global Redirect and Page Title.)
9. Sitemap and XML Sitemap. Opinions differ on the value of XML Sitemap, but I see no harm in it -- and in fact, I can pretty well document that I started getting a LOT more crawler traffic after enabling sitemap submissions for all available engines. Whether that translates to actual traffic is a function of content.
10. Make sure your front page RSS feed is discoverable. In most Drupal themes, as soon as you make something other than "node" the home page, the front page RSS feed isn't discoverable anymore -- you will need to add either code to your page template or to the template.php file of your theme. Don't have a link to the snippet handy, but you can google "drupal 6 discoverable rss feed". (On a related note, make sure nodes are getting shown in the front page feed by setting the default value for "Promoted to Front Page" to yes for every content type you want to be shown in the feed.) (Note also that you can bake your own feeds with Views.)

[edits -- sorry, keep thinking of things I forgot]

Drupal IS configurable and infinitely themable, but that doesn't mean the initial, out-of-the-box experience shouldn't be optimized! Flexibility is not a justification for complacent default experiences. For example, Microsoft's mantra is support all users by exposing all the knobs - the defaults aren't really important if the configuration can be changed and that logic surfaces in the genericism of their products. Apple's mantra is make the default configurations spectacular and don't even bother surfacing the configuration controls - make it amazing out of the box and let the critics pound sand. Apple's market cap recently passed Microsoft's even though their market share is a percentage of Microsoft's. And why do so many developers work on Macs? To be fair, Apple's business model is extreme and closed. It's bottom line is its only concern. That's not the community that Drupal grew up in, nor should it strive to emulate this model. But Apple's singular focus on perfection is admirable. It's not beyond us to make the Drupal out-of-the-box experience spectacular before one even starts talking about modules and configuration settings.

Both are great applications but I feel it is unfair to include them in the same conversation. Drupal is overkill for some sites and WP is underkill for others. They serve very different purposes and the sites that are built with them have very different requirements.

As far as SEO goes, the individual theme matters a bit more than the application. Drupal does offer greater control and provides more features--though at a cost of time. However, there are countless numbers of sites on either platform that are doing very well in the search engine results pages.

You wouldn't select either based on SEO. You would choose based on the requirements and objectives of the site and the resources (staff, skill set, finances, etc.) of the client.