The website is generally updated to display the features when the new version goes out of beta. While it's in beta, the developers will post (in the sticky thread at the top of this forum) what the new features are. Changes in the 'Z' portion (the bug-fixes) are sometimes accompanied by posts here detailing what exactly was fixed.

For instance, Chris posted these as the new features of 2.7:

-Remote queueing: if an uploader is too busy to handle a download request, it will queue you. The uploader then serves downloads in a first-come, first-serve basis. This feature is compatible with the queueing schemes used by other vendors.

-Resume from library: you can resume incomplete files in the library with a single button press.

-Safer resumes: LimeWire keeps track of the hashes for all incomplete files. This reduces the chance of a corruption when resuming.

-No updates in 2.7.2 or 2.7.3 or beyond will add any features, they'll just fix problems that were accidentally introduced when the code changed to include these.

I don't disagree that it's useful to have the actual bugfixes listed, but it often can take much more time to describe, detail, and update a list than it can to fix the problem.