If your TOGC 25 man geared, the flask of mojo is a great tool to give you some great flexibility for learning ICC and having some leg-room to overheal a bit. I say that because with over 3k unbuffed spell power the frost wyrm flask doesn't really make or break a heal unless you're focused on main tank healing meanwhile if you're healing an entire raid (and healing a bit more since its new content) the mojo seems to really help.
Thats my 2 cents 2 clears of ICC 25 and 10 man..