Sapu's been working hard on the release version of TradeSkillMaster and it's getting close. Here's a link to the official preview at the TSM home site.
TradeSkillMaster Release Version Preview
Sapu was good enough to send me a pre release version to play with. Here are my thoughts after playing with it for a few days.
The most noticeable change is the auction house part of the User Interface has been completely redesigned. This is a huge change, everything has been moved around and it takes some time to get used to it.
The configuration window (which opens when you type /tsm) is mostly the same as before. A few things added or moved but for the most part it's the same old familiar configuration UI.
It's hard to say for sure but it seemed to me it's faster and less laggy than before. I'll be able to say more about that after running it when the server is most crowded (prime time raid nights Tues-Thurs).
A few features seem to have disappeared in the process. I don't know if they've been dropped for good or will be added back at a later date. One thing I really miss though is the ability to manually change post prices on the fly while doing a post scan. (Edit: The author says this feature will be in the release version)
Many of the changes are IMO major improvements. In particular I like how the sidebar window is gone (mostly anyhow) and has been replaced with an auction tab.
There are a few details I'm not fond of but this isn't a review, the new version hasn't been released yet and many of those details could easily be changed by release so I'm not going to get into that now. They're mostly little things anyhow, like a double click where I'm used to a single click with other addons or a key piece of information I want to see missing from a scan list.