They haven't kept pace with the other classes. They're much stronger on multi-dot fights than they are on single target fights. Fights with much movement (LOL ALMOST ALL OF THEM) are horrible for boomkins because they nerfed the crap out of Moonfire/Sunfire due to PVP concerns.
Honestly, the balance spec is horriterribad to play as well. I'm going to be a druid in WoW until its end of days, however that doesn't mean they're the bees knees. It's rapidly apparent that the design time alloted to classes has been spent elsewhere. They're not "broken" per-se, but they aren't nearly as fun to play as other classes. Another hybrid, the priest, has many more interesting buttons to press in their primary damage (shadow) spec.
Boomkin is MF, IS, That-one-spell-that-used-to-hit-like-a-truck-that-i-cant-remember-the-name-of-but- the-free-proc-is-called-shooting-stars, Starfire till eclipse, wrath till eclipse, rinse repeat. use that one spell and refresh dots as appropriate. Cast trees before hero/lust/timewarp, cast starfall on cd, but try to time it with lunar eclipse. It doesn't SOUND that bad, but when you go to play it, it is THAT bad.--
flickr | 'Cause I've been waiting, all my life just waiting
For you to shine, shine your light on me