I briefly played as a destro lock pre-5.0 and hated soul fire and it's buff with a burning, intense passion. The new destruction playstyle is amazingly fun and interesting to play in raids. The spec pure single target is lackluster, but it's potential complexity on fights with more than one mob or burn phases is bar none.
If you want to watch some (decent to great) destro raid-play you can look up my name on youtube. I have vids of most of the fights this tier on heroic as destruction (with quite a few 1st/2nd destro parses being the gameplay)
I love destro and I hope that they don't change the playstyle, just the numbers. We need a single target buff (my vote is on either Immo or Incin damage), but our cleave is exceptional.