It averages 15 weeks (+2 days) between patches, so I expect 2.5 around February 12th, and 3.0 near-abouts May 30th (using the information below). That's including giving 2.5 the full patch cycle that all the other patches get, but if it's a light patch they may decide to cut it short and drop the expansion in the middle of the cycle. I don't see them doing that, though.

2.0 Aug 27
2.1 Dec 16: 16 weeks (-1 day) 111 days
2.2 Mar 27: 14 weeks (+3 days) 101 days
2.3 July 8: 15 weeks (-2 days) 103 days
2.4 Oct 28: 16 weeks (+0 days) 112 days
2.5 Feb 12: 15 weeks (+2 days) 107 days (estimated)
3.0 May 30: 15 weeks (+2 days) 107 days (estimated)