I'm very impressed with the functionality, versatility and freshness of MegaLauncher 5.5! IMO, the first real competitor to ZLauncher, which I've enjoyed using for a couple of years. I'd like to see a better iconpack solution, something like ZL's iconsets would be much better, but other than that, ML5.5 is great! I haven't tried all of it's goodies, but it appears it could eliminate the need for separate zip, backup, file management and launcher utilities.
ML5.5 provided me with the opportunity to finally give HP Skin Studio a try. Although I would choose to stick with Festus440's ZL Theme Maker, due to its ease of configurability and because I'm simply used to building ZL themes with it, I have to say HPSS is a wonderfully written and executed Skin making application. Creating a skin for Megalauncher was a breeze. The preview screen is a huge bonus. The next update is supposed to include a "dynamic" preview screen, which I suppose will mean the buttons will be tap-able so as to make viewing the buttons in their various states even easier.
Here are a few screenshots of my Cool Water skin for Megalauncher 5.5:

Shown with the Cool Water VG and Status bar.

Split screen MegaLauncher view.

Full screen MegaLauncher "tree" view.
I'm uploading ML Cool Water at PalmGear tonight. Hopefully it'll be available in a day or two. I'll post the link here once it's up.
Edit: The skin looks nice in landscape mode, which I'd love to show here, but there is no "Landscape" compatible Screen capture utility for the TH55, as of yet.