Well yes, it would appear that the 170/190 family is the only game in town. punters are going to love em comfort wise (rode down the back at Paris on a journo jaunt) Crews are going to love em (once the avionics software is sorted). I had a go with 006 last month and it was a joy to fly, really a lot of fun even in direct law...
However, it's also worth taking into consideration the political side. Can you imagine for example, the wailing and gnashing that would ensue if Air Canada ordered EMBRAERS over Bombardier offerings?
The rumors I've heard suggest that the the Star buy is beginning to break up....Lufty for example would like to stay with the CRJs for the smaller end, (LCL) already has loads of CRJ100/200/700s, and leans toward Airbus at the top end (commonality you see). Plus again the latter is homegrown (don't forget that before it's demise Lufty was firmly in the Fairchild Dornier camp for its 70-100 requirement. United - well who knows what hey want. Varig naturally (if still around) will lean firmly towards SJC and so on and so forth.
Incidentally going back to my earlier point, I have heard on reasonable authority that Air Canada is going to order 717s for it's DC9 replacement but then it was a Boeing (LB) guy that told me.