It's not that I don't like the original 5D, that's just the prevailing opinion among internet gear heads.

If you want the best image quality for the lowest price (in terms of a camera body), your best bet is probably a used 5D. And really, all of those AF & speed issues, may be a complete non-issue for you (and most photographers really).
As for dust, sure the 5D doesn't have the new 'shake the dust off' feature that all the new cameras have...but I wouldn't make a big deal of that. It just means that you may have to clean your sensor more often. I have 20Ds and I really only clean their sensors two or three times a year.
As for the image quality of the XSi vs the 60D....I really don't know. I've heard complaints about the 60D and how it's image quality isn't any better than the 40D/50D, and may even be worse in some aspects. Probably a result of trying to cram so many pixels onto the smaller sensor. I hear that less about the 7D, which I think has the same sensor...but it's one reason I didn't upgrade to the 7D. There are plenty of resources for comparing the image quality of specific cameras (and lenses), so I don't think we need to discuss that too much here. (especially since I haven't used either one, besides seeing my students use them in class).
As for waiting for Canon to come out with a new model, to see what that will do to the market....good luck. They are very tight lipped and only leak info a couple weeks before they release the new model officially. I speculated in another thread that maybe a new model is on the way, because the local cameras stores in my city, are discounting the 5DmkII $700 off their list price. (now $1999). But really, nobody knows. It's typical that they make their big announcements around the time of the big international camera shows.
***OK, I just did a quick read over at the Canon Rumors web site. They're saying that the recent discounts are not a harbinger of replacement models...but that 2012 will be a big year. 25th anniversary of EOS cameras, Olympics in London, etc. Possible replacements for the 5DmkII and 7D. Maybe as early as Jan or Feb...but again, Canon is tight lipped and these are only rumors.