The page has gone live. The tickets will go on sale on April 25th at 10AM PDT. This would be the first event without Scott Forstall, the man behind the iOS all these years.
Analyzing the logo, there are very high possibilities of multi-colored Macs, and other iDevices, and also, the company is expected to announce the much talked about iOS 7, Mac OS 10.9, Aperture 4 (Or 3.5 May be), iPhoto 10 and much more.
There are also talks that the company would be bringing iOS closer to Mac with this release, by bringing iBooks for Mac OS X, Apple Maps on Mac and much more. At this time, this is the information I have, but stay tuned for more. The excitement begins from now.