Definitely watching Gundam Unicorn
Without spoiling it for you, I'll only say that you won't be disappointed, especially if you've already seen enough Gundam series to spot the hints/shout-outs. Heck, the dub trailer alone was enough to "make" me pre-order the Blu-Ray ...
As for Spring 2010, I'm not interested in any of the series - not even the ones on noitaminA (my usual staple block). With the exception of the VOTOMS OVA, I'll probably be sticking with FMA:Brotherhood/DuRaRaRa!!/Kimi ni Todoke.
Speaking of which, chapter 105 of the FMA manga should be published next week. After what happened in the previous chapter, I'm eagerly awaiting to see how this will pan out!

Sometimes it's good to have something totally different each episode! Animation is really nice in HD too!
The various battle themes seem to fit the battles pretty well aswell.