Speculation remains rife over what the opposing boxed set army will be.
There is also wild speculation over which (if any) codex will be released before 6th ed arrives. Apparently there hasn't been a new codex for the last 6 months, which is a little out of character for GW. Several people claim Chaos is coming out as people working at printers have leaked info about it. Others claim Tau will be the next one as they're the last race to been still stuck on a 4th edition codex.
Personally I think it would be crazy for GW to release a new codex for 5th just before 6th comes out, but if the leaked version of the 6th ed is to be believed (see this previous post) there will be conversion rules for them so they may not think it matters.
We will see what transpires.