I just reviewed this album at Play.com so I'll just copy paste my impression here:
An alternative approach to Coldplay...
I definitely see why fans feel divided about this new album. While rather different from the amazing Viva la Vida in its celebration of life and death, Mylo Xyloto definitely breathes an alternative almost playful side to the band's usual themes.
It's different from what we're used from Coldplay but you can still hear a familiarity to it. If I had to compare it to other bands, I'd say some tracks have a remarkable Sigur Ros feel to them, what with the metallic echo sounds and chorus in some select tracks. The duo with Rihana was done well, against (many) dreaded expectations.
Overall, a different approach to a great band in an album that (I feel) gathers a little piece from every corner of the world. Not their best work, but you shouldn't let these words discourage you if you're a true fan. Also, they've set their bar high with their last album, so it will be difficult to break those odds.
Other than that, the album art is rather well accomplished - still abstract and perhaps a tad too colorful but I'd say it goes well with the music itself. The lack of lyrics kinda irked me because I always liked to be able to follow the songs but, at the same time, if we go with the Sigur Ros comparison, you can understand they just want us to feel the music rather than be worried about the words. That or they're saving up on printing ;)
Favourite tracks so far include:
Paradise,
Up with the birds (especially the last half) and Charlie Brown:
Click to view
Of course, I could be wrong with my access as I haven't read anything on the album's meaning.