We're currently at Bitcoin Core 0.9 What will it take to get to 1.0?
Edit: Not the wallet, the protocol.
I don't really distinguish between
the wallet (Bitcoin Core) and the protocol regarding the status "beta" simply because Bitcoin Core is currently viewed as the reference implementation of the protocol.
I'm sure we'll see Bitcoin Core 0.10, 0.11, and 0.12 first if this remark by Gavin from 2012 is anything to go by:
The things on my "good enough to be called 1.0" list are:
+ easy enough for my grandma to use
+ secure enough that it'd be hard for my grandma to lose her bitcoins, even if her computer is infected by 11 bitcoin-stealing trojans and then catches fire and explodes.
+ past the December block-reward-drops-to-25