I was booked for May 2014 and have thought a lot about this, so I'll share my perspective:
If you use how long it took them to do the GF courtyard pool as a benchmark (this took over 7 months - from August 2012 to early April 2013) and they start on the Nanea pool in January, the chances of it being open by May are slim.
Keep in mind that they're not just redoing the pool. From what I understand from reading Tikiman, they're redoing (and retheming) the whole area between and including the pool and GCH (which includes putting in a Trader Sam's).
Your better hope, IMO, is that they end up delaying this. But given the speed at which things are starting to move, I'm not as optimistic about this as I once was.
Along those lines, I've changed my ressie from Poly to CR garden wing (I may change back if construction issues end up being less intrusive than I'm currently envisioning - FWIW, going forward, even with Tahiti and Rapa Nui out of the picture, I think it will be easier to change from CR to Poly than from Poly to CR).
Anyway, just my $0.02.