Thanks for all recommendations!

I own a G11 and while I understand that Micro 4/3 are indeed a step-up, I feel like going towards a DSLR directly instead.
I've been using one (550D) quite extensively in the last month, while improving my knowledge on aperture, exposure, focal length, and experimenting, and I really enjoyed it.

Finally, I really would not know what to chose between Canon and Nikon, as I understand all depends on your tastes and subjective likes and dislikes. Which, as a beginner in the DSLR, I don't have yet But, my gf has Canon body and lenses (which I'd be able to use), so I guess in my particular case Canon is the way to go. Also, I became somewhat familiar with the 550D user interface. I've always had Canon compact cameras, and I see a lot of the G11 user interface logic in the 550D, which makes it all easier.
I think I would not mind a slightly larger body than the 55D, and the 60D does have that. In terms of camera weight, I also tend to like plastic over metal. But, I wouldn't mind a resistent body that can survive longer. But, I guess, can't have all.

As a side note, all my friends owning a DSLR are using Canon. That per se is not affecting my choice (my gf having Canon is, in fact), but I am curious if Canon does have a larger mkt share in the XXXD XXD segments?

Bruno, when is Photokina?