Cata healing questionsFollow

The heart of my question is this:

Are Holy and Disc still each viable PvE healing style or have things changed to the point where it is a noticeable advantage in holy PvE healing?

Just from what I've seen and read, holy defiantly seems to have been given plenty to make it a very good 'all-around' healing spec (particularly with chakra). From what I've heard about Disc, it sounds like shielding has been scaled back a bit. I'm mostly curious, I was thinking of switching to holy anyways (only healed as disc and my other spec is always shadow).

Guess my next question would be how has the healing style changed? I remember (stopped playing almost a year ago..) shielding was the main 'heal' I used, followed by Penance for big hits and flash heal when Penance was down, along with PoM whenever it was up, but is most 'condition normal' healing dominated by the new "Heal" spell?

I'm figuring that if disc has changed significantly, then I'd go holy because if I'm going to learn a new healing style, might as well go for the one where I'm least likely to fall into old (probably bad/inefficient) habits.