They are rolling up 2.4 into the 2.5 release as they were building the code versions in parallel. Since the paypal subscriptions billing plugin delayed 2.4 they simply decided to roll it into 2.5 and release 2.5. Keith did post screenshots of the new 2.5 so one can only presume they will be releasing it anytime now.
I've heard that ClientExec's people have planned to release Version 2.4 which included Paypal subscriptions with some more features but they’re thinking to include that with their ongoing projects they are working for also Version 2.5 along-side of 2.4. They are going to release it probably in third week of June.