According to Notcom, he is working on a complete rewrite for TinyUmbrella. The goals are:
MUCH better linux support, unified device access across platforms, simple and elegant UI, automatic support of new firmware.
All of this will take some work, but will take a little bit of time. Bear with me!
Click here to download TinyUmbrella 4.30.04 for your Windows. Click here to download TinyUmbrella 4.30.00 for your Mac OS X. After downloading TinyUmbrella 4.30.04 simply follow the step by step instructions posted here to save Apple TV SHSH Blobs.