If you don't want to bother reading the page. It's just a publicity/marketing skin on various google properties for Star Wars.
Well duh.. The point is that its cool to a star wars fan.
So without signing up...what is it?
just Star Wars themes on your Gmail and Calendar accounts
Its pretty much just theming of various google sites. The subtlty of some it is cool. Like the volume control on the Youtube videos plays the light saber sounds whenever you try to change volume.