Of course I am only speculating, but here are some of my reasons for believing this...

1) Since the Party split, the two have become very close in terms of players with less than 3000 players separating the two at times. In the Past, pokerstars has grown at a higher rate than Party, and there is little reason to believe that this will not continue.

2) Pokerstars is going to implement a reward program for high volume players which will lure many players from that site

3) The lobby ugrade described by Lee Jones in the 'Dear Lee jones' thread will please many former party players and stars will capture some players this way. Most likely, tournamnet players who were finding the cumbersome to multitable given the poor interface. Similarly if they do eventually implement draw software. This would steal players from UB and FT

4) January will be what it usually is... A fish drainer. They will all have spent their extra cash on christmas presents and Party will likely lose more players from this than stars will.

Fidel