Some people seems to be confused about this whole Blender 2.5 version naming scheme.  This roadmap (stolen directly from blender.org) should clear things up a bit.

Blender 2.5 | 2.6 roadmap

Basically, 2.5 will be a series of transitional releases, the final stable release will be named 2.6 in all likelihood.

As with any transition, there is a bit of resistance to the new interface, long-time users are complaining that they can’t find what they are looking for (like SubDiv), others wonder why features (such as radiosity) are simply removed without justification.  I am an early adopter of the BLender 2.5 series and personally I am very happy with the direction Blender 2.5 is going, it’s actually a lot faster to work in the new version, since the user interface is arranged much more logically.  And thanks to multithreading, being able to render, animate, and model something at the same time is amazing.