We almost let this one slip by.  Techtool, the Gold standard in Macintosh hardware diagnostics has finally started shipping their version 5 upgrade.

So what is new? (from MacUser)...

Beyond the new interface, you can now identify files that reside on bad blocks, you can see a trash history to help recover deleted files, you can check for specific types of file corruption, and set up an automatic monitoring system to watch the free space on your disk drives. A new interface when running all tests shows you all the queued up tests, and you can selectively disable those tests you don’t wish to run, even after you’ve started the (lengthy) process of running all the tests.

Micromat still lists Techtool 4 as current on their webpage but allows you a free update to version 5 if purchased in 2009.