I'm about 50% finished with my first play through of Xenoblade Chronicles and I'm already about 110 hours in. I'm enjoying the game so much, it has quickly become my favorite RPG of all time and one of my Top 5 Favorite Games of all time. I didn't get the battle system at first, but now, it's really really great. I think it has a lot of tried and true JRPG elements, but without a lot of the hassle that people complain about JRPGs. For example, fast travel, auto-healing between battles, and being able to change time instantly. Those things are elements that other games could really start to use.
My only complaint with the game is the character modeling. I think the characters themselves look awful, and I'm not hating on the Wii. I think the environments look gorgeous. It's one of the most artistically beautiful games I've ever played. The fact that if you can see it, you can go to it is amazing. The whole world is huge, and extremely well made, and extremely creative. But man, those characters look terrible. Especially their eyes ... yuck. I think that's a theme I'm seeing a little with X as well. The world and the enemies look absolutely stunning, but the character models look out of place. It's a minor gripe, and it won't take away from the game.
The only other thing I've noticed is that — so far — the music does not live up to the original. Xenoblade Chronicles has my favorite soundtrack of any video game ever (my previous favorite was Wind Waker, as reference), but from what I've heard in the trailers and on the official site, I'm not sure X's music is going to be nearly as good.
All that said, Xenoblade Chronicles X is my most anticipated game of the year (yeah, more than Zelda U!) and maybe my most anticipated game ever. I simply CAN'T wait for it.