Google hinting: rel=nofollow

A follow-up on Google hinting: some indications that Google will announce support for a rel=nofollow attribute.
Links tagged with it would not count in the PageRank calculation. So, it could be used in wikis and blog comments, to discourage spammers. It will also affect many legitimate links, from non spam contributions to these wikis and blogs, but that seems to have become a necessary trade-off. Will we see a degradation in search quality, as a result of this (if it becomes successful)?
Sam Ruby points out that spammers won't care, and I think it will be true at first, but in the long run it may help. Worst case, it'll force spammers to spam even more (to achieve the same amount of Google juice), which will be a good incentive to figure out even better solutions.

I'm impatient to see the official announcement. To me it's a great sign of leadership and community participation that Google introduces their first contribution to the design of the web. Let's see if other search engines and the major blog and wiki software providers will decide to support it.
Please, bloggers, don't get disappointed if spam doesn't improve in the next year. It'll take time for 90% of blogs to get updated to this solution, if ever, and only then will spammers really start to suffer from it.

Update (2005/01/19): Google, MSN Search, Yahoo, SixApart and some more have made the official announcement. A MT plugin is available (via gemal), so I'll be adding support here shortly. It looks like most other blog tools decided to support it too.