My question is more directed towards those who have play time and extensive knowledge of the beta so far. I have started a priest and been gearing for disc as i've hit 80 with off-spec shadow, I want to keep my off-spec shadow.
Now I know that the priests Disc healing tree and Holy healing tree fill two totally different niches. I am just curious to find out which of the two healing specs you think you'll find more effective in Cata. And is Disc going to become more of a "tank" heal along side Paladins again as well.
I'm not sure where you are getting the idea of niches. The whole point of 4.01 (Cata) is to blur the lines and roles of people. All healers now have a
1) low cost, medium cast, low heal spell
2) Medium cost, slow cast, high heal spell
3) High cost, (oh crap) fast cast, medium heal spell
4) AoE heal ability. Yep, even paladins.
The difference is now in the style. Mainly HoTs but now more direct heals for druids, Shields for Disc, Mainly direct heals for Holy priests and now more HoTs (via mastery), resto shamans are relatively unchanged, and Holy Paladins are very proc/HoPow-for-free-heals based.