I thought I'd start a few thread about various issues that need to be thought through, along with my own observations about them.
First, how and where to view and/or edit the nodes?
My vote right now is that both should be in the user profile. My early sandbox efforts treated each node-profile content type as a user category, placed in its own tab on the user page. Not just on user/edit page, as with profiles now, but also on the user/view tab because the nodes can get much too large to just run them all together on a single view page.
It is possible to do this without much trouble (I have done it), so it is just a question of whether or not this is the desired behavior.
It will maybe confuse some people who expect to edit a node at node/11/edit instead of user/11/edit, but I think that is just a matter of getting used to things.

Comments
i like the way you
i like the way you propose.
my aim is that we are able to replace the drupal-profile completely.
because then you dont need modules like members.module or the profile.module to show a list of users.
you can use views or something else instead.
the user dont even need to see that this is a node, he should think this is part of his ore another users' profile-page(s)
Tobias Maier - http://tobiasmaier.info/
core profiles have a lot of issues.
The sub-local tasks (tabs) are IMO one of the worst usability issues ATM in Drupal core.
We can, off course follow the current path (my code has the placeholders to do so, but some technical problems held me from working that out completely) in Drupal.
But IMO we should also offer a much improved system.
http://www.webschuur.com | http://bler.webschuur.com
tabs
for quite a detailed profile it would be ideal if it's possible to split it up in several tabs - but to improve the usability the user should be able to fill it out in one run.
so in my opinion providing a kind of workflow through the tabs while validation is done on each step would increase usability.
Path
I don't think the path matters to most users at all. the change between node/n/edit and user/n/edit isn't much, and as long as the displayed page is clear it shouldn't matter much.
but
even if the user doesn't care perhaps it matters to the admin?
it's easy to link tu user/uid/edit/category from somewhere, but it's not that easy with node ids..
both *might* care
... so who are we to decide if it matters or not?
Developers tend to forget way too often that the way they thing Stuff is done best, might not be the Best for all people in all cases.
Hence I think we whould not enforce any scheme, but leave all possibilites open. We have the menu system, sone settings and themes to provide all the options for those who need them.
Now, that does not mean that we should not design a good working, nice default, though!
http://www.webschuur.com | http://bler.webschuur.com
Or make no choice, but only offer good defaults?
Another option, and one that IMO is preferred, is to NOT choose one way of doing stuff.
Which does not mean that we should offer large ranges of options in the UI.
Where to show stuff?
We could offer theme apis to allow people to easily render userprofiles anywhere. (my code has the starters for this already).
We can offer normal APIs so that other modules can very easily pull in (pieces of) profile nodes.
We can offer hooks to allow other modules to change stuff in profiles (Since we have nodes, that is nearly "for free").
We should develop proper Views definitions that allow all sorts of nice renderings.
Then as last point, we could make sure that the normal "user/12" page contains some nice summary, fully themable, and fully overridable (in the theme).
Some examples of the working profiles as nodes, look here:
http://incubator.beauty-coach.nl/area/directory (a view with all the profile nodes) http://incubator.beauty-coach.nl/gebruiker/2 (a themed user/123 view)
Where to edit stuff?
This too should be not hardcoded. the current way drupal handles this, in the category sub-tabs is for some people a good solution. For others (including me) this is horrible thing. It depends on your audience etc.
I see three options, which we can cover in one good setting:
* all in one, SINGLE form under my account >> edit (very usefull of you have a few small nodes)
* all in separate pages, as categorised subtabs under the my account >> edit >> corporate details
* all under the normal node >> edit tabs, accessible trough a side block that can simply be rendered on a profile page. (my code has this already)
Where to insert stuff?
Required fields should all be rendered on the registration page.
We must offer some kind of admin UI to select other fields to render on the registration page.
On registration, the nodes that receive content from that registration form should be generated. Node w/o any filled in fields might (optionally) be generated then too.
http://www.webschuur.com | http://bler.webschuur.com
My experience
I've had a few problems with the whole profile area over the past year or so. The differentiation between nodes and users causes issues not just for editing information but can become even more complex with certain modules that act only on nodes .etc. such as node map / user map with the gmap module. I tend to just do my best at Drupal theming to try and get everything to look similar both the profile nodes and the user accounts.
Anybody know if there are going to be any big profile updates in Drupal 7?
Drupal development at iNet Digital
Looks like it is going to be
Looks like it is going to be pushed in D8 sadly.
Big threads here: http://drupal.org/node/301071 & http://drupal.org/node/394720
I had the same issues, so I basicly rewrote the inner api profile module. It is now working great.