Well whaddaya know? Despite the generally negative outlook this film has had since director Bryan Singer jumped ship from the X-Men franchise to spearhead its development, the early reviews have been overwhelmingly positive. See Rotten Tomatoes for an aggregation of reviews, where it's currently at 94% positive. Glowing reviews include those from Time, Newsweek, Variety, Hollywood Reporter, and Ain't it Cool.
I haven't been blown away by any of the previews, but I'm more than a little excited to see this now... All of Singer's previous films have been very good, and there's little reason to expect otherwise from this one. Fingers crossed.