(1) Security for end consumer. Might seem weird that I highlight this first and foremost, but I think that security from a tech savvy standpoint is the inverse of that from a consumer standpoint. What? My Bitcoins just disappear? Someone can hack my computer and all my money is gone forever?

(2) Usability. Classic problem from Linux standpoint, hard to take something w/ current design to something that is both incredibly usable and secure for grandma to use.

(3) Stable long term demand. Right now we don't have that. If there is major adoption of Bitcoin (including merchants actually holding Bitcoin) in the developing world we may see that (watch Kenya this year, for example).

(4) Programability. This is what Ethereum (and, to a lesser extent, Mastercoin) are working on.

(5) Less transparency. Actually I don't want people to know how much money I have and what I spend it on.

(6) Price stability. I don't know how you get here with Bitcoin.

(7) Instant clearing time.

(8) Zero fees. I guess this exists in some alt coins (i.e. Doge) because there's a presumed lack of possibility of a double spend.