Language-aware links - does anybody have a solution?

I keep running up against these issues... Here are a couple of scenarios:

Scenario 1

I create the node Welcome in English and Bienvenido in Spanish. The content of both nodes include a link to About us which is currently only available in English. Months later, About us gets translated to Spanish and becomes Sobre nosotros. Nobody remembers to go back and update the Bienvenido node and change the link to point to Sobre nosotros instead of About us.

So what it seems is needed is a way of saying something like {NODE:3} which gets displayed as a link to Node 3 and automatically changes to a link to the correct translated version of Node 3 if and when it becomes available in the future.

Scenario 2

For whatever reason, somebody goes to www.example.com/es/node/1 where Node 1 has English content. This will display Node 1 in English with all other parts of the page (menus, blocks, etc.) in Spanish due to the es prefix in the url.

• Should the visitor be automatically be redirected to the Spanish version of Node 1, if it exists? (I don't think so.)
• If not redirected, how should any links included in Node 1 content be shown? For example if Node 1 contains a link to Node 3 (English) and Node 3 has a Spanish translation as Node 4, should the link displayed be automatically changed in a similar way to Scenario 1 above?

I don't think there is an off-the-shelf solution for these issues, either for D5 or D6, so I'm thinking of creating one (probably as additional functionality to Language Sections, but I'd like to get some opinions first.