Version 2.57b was released a couple of weeks ago. This version has over 100 significant bug fixes. You can get your copy at: Blender 2.57b Download
One of the problems I’ve had with Blender is my need to run multiple versions. Until just recently building for Myst-Uru Plazma required 2.49b. Also, the Collada exporter in 2.49b is reputed to be better for Second Life. Then there are the JASS and Primstar tools made by Gaia Clary and Domino Marama which have dependencies on Blender and Python versions.
Plus I have other programs that have interdependencies on the Python version installed on my computer. Updating Blender was getting way to complicated. I was breaking too many things I wanted to work on.
Fortunately there is a better way to deal with all these problems. If you notice the download page has two distinct versions, an INSTALLER and a ZIP ARCHIVE. If you get the ZIP ARCHIVE you do not need to install it. The archive is setup to unzip into a folder and just run. Everything Blender needs to run is in the archive. The right Python version, Python scripts, and folder links are in Blender so that it just runs.
Once the folder is unzipped be sure you haven’t created extra folder depth. My Zip Genius tends to do that or at least the way I work it does. You want to end up with shallow folder tree. Mine looks like the image.
When the folders are arranged as you want them, find the file blender.exe. Right-click it and drag it to your Task Bar or desktop and drop it. Select create Shortcut. This creates a link that allows you to run Blender without having to drill through the folders to find it.
These are the notes that tell you what has changed since the last release. Several things that were crashing Blender have been fixed. So, this release is more stable than 2.57a. Reference
The Deform Modifier has a fix. A number of tools have fixes and now work in more than one mode.
Dolly zoom has been changed… fixed… improved… something. Its unclear and I guess I haven’t seen the problem.
The new 2.5x versions have a new thing that allows Python plug-ins to be added. Blender.org has a library of add-ons. You can find it here: Blender Add-ons.
What you may not have noticed is many of the Add-ons are included in the Install and Archive. In the top menu click on File -> User Preferences… -> tab Add-ons. You can select add-ons to turn on or off. You can expand the Add-on item and see a little more information about it. Best of all is there is a link to more information and usually instructions for using the Add-on. Often there is a video. Watching the videos is instructive.
If you have only been using the basic Blender, turn on some Add-ons. You will love 3D Nav and other add-ons. They make using Blender much more enjoyable.
There is a good 28 minute video of 2.57’s new features. See Vimeo: Blender 2.57 is Released – Video Overview
It is probably worth the effort to put this new version on your machine and try it. Using the Zip Archive makes it a trivial upgrade and doesn’t affect your other installs.