I think they were suggesting Q3 for the new Now TV box with Freeview built in.
I would say it is unlikely that the number of channels will grow much on Now TV as a) it will push the cost up beyond what is currently an attractive price point, b) they would prefer revenue to stay with channels Sky own or co-own in the UK, c) we'll probably see other content owners offering their own apps / services.
TV Player Plus for £4.99/month covers most of the popular channels that aren't on it and is rolling out to quite a few streaming devices over the next few months apparently :
http://www.tvplayer.com/channels/.