The new v2.7 release of the FuseIT SFDC Explorer has some new features.
Run a single test method in isolation
After running tests, either in synchronous or asynchronous mode, you can right click on in individual test method to get the context menu. This will give you the option to run just that test method in isolation. See The Holy Grail of Testing in Salesforce.
Basic Apex Class editor
There is the new Apex Classes tab that has search and editor. It's no where are full featured as something like Mavens Mate in Sublime, but it might be useful in a pinch if the developer console is misbehaving (or you want to bypass certain permission restrictions).
Highlighting code coverage lines
For larger Apex classes, where it can be difficult to find the largest blocks of code that need coverage, I've added coverage markings to the scroll bar.
It's still a bit of a work in progress getting everything aligned correctly, but it should make it easier to scroll to the blocks of lines without coverage.
Alpha version of an Org Metadata diff tool
Here you establish a secondary Salesforce Session. Then, using the diff button the tool will pull down the metadata for both orgs. Once stored in the file system it is passed off the the Diff tool of your choosing.
Miscellaneous
There are some general enhancements to Wsdl2Apex to deal with WSDL's that have multiple imports of the same namespace. Support for 2 character pod identifiers. And some generally improved error logging.