It's too early to tell, haven't spend enough time with some recent releases, but it's probably between Road Salt II, Heritage and Snowtorch, the last one would get my vote if I had to chose now.
The new Dream Theater is again worthless to me (as all of their albums after 6 Degrees), Sym X and Steven Wilson are interesting but didn't really grow on me yet.
I was really looking forward to Testimony 2, but I think it was a letdown. Just like Dream Theater, Neal keeps on doing the same trics over and over again and these tricks simply went over my individual expiration date.
Other bands with new cd's, maybe worth to mention: Pallas, Magnum, Pendragon, Evergrey, Blackfield, Wolverine.
Lover's End by Moon Safari was released a couple of weeks before 2011, otherwise it would be very simple; I rate that album being one of the best prog.albums ever.
I think Rush is coming with a new album? Let's hope that one will be the album of the year, we've had a lot of releases so far, but too many were dissapointing and mediocre at best