Chase has just flipped the switch again to turn on the 50k bonus point offer:
http://www.flyertalk.com/forum/20904255-post230.html
Note that you cannot apply now and wait until January to cross the spending threshold. There is a time limit of about 3 months for crossing that threshold.
Furthermore, waiting until 2014 to earn a Companion Pass on bonus points carries two risks:
1. Southwest might find a way to exclude signup bonus points from counting toward the Companion Pass (unlikely, since Chase would certainly prefer all its customers' points to count in full), or
2. Southwest might drop the Companion Pass benefit from the Rapid Rewards program, not allowing any Companion Passes to be earned in 2014 and beyond. This would be a definitive way to deal with the beginning of international flights on Southwest. Southwest might create some kind of sweeter to soft-land members who would otherwise have earned a Companion Pass, but I don't know what that could be other than a third Elite tier.
I may be a pessimist, but I rate the probability of one or both of these changes at about 50%. I am amazed that the Companion Pass has continued this many years without significant devaluation. I don't think any high-value award in the loyalty program universe has lasted this long. Long gone are Marriott Travel Packages, Hilton ALON and GLON, super-expensive resort hotel rooms at standard redemption prices, last-seat flight awards at standard redemption prices, and of course award travel on the Concorde. The Companion Pass has outlasted them all.
If you're planning on trips to Las Vegas with your Companion Pass, you might want to gamble by waiting until 2014 to qualify. History argues that you shouldn't bet against continuation of the Companion Pass. If, like me, you fear that all good things must Pass, make your move now.