That screen is a kernel panic
It could be several things, there is a bad firmware update going presently that could explain your problem
1: Locate your firmware for your model on this page and download, to another Mac if necessary
http://support.apple.com/kb/ht1237
2: Follow the instructions on this next page to burn a cd and install it or if your Mac works, try to install it without the cd.
http://support.apple.com/kb/HT2213
The next thing to try would be to go back to Snow Leopard and see if that clears it up, if not it's the firmware.
How can I uninstall OS X Lion and go back to Snow Leopard?
1: Copy your user file folders (Documents, Pictures, Movies, Music, not Library) to a external blank Disk Utility formatted HFS drive (not TimeMachine) and disconnect all drives. Make a note of your username and hard drive name. Write down any essential information like passwords stored in keychains and product serial keys.
2: Stick the 10.6 installer disk into the machine and reboot holding the c key down. Second screen in choose Disk Utility from the Utilities menu.
3: On the left select the hard drive makers name of your internal boot drive (important) then click Erase and Erase... button (if you want to wipe the drive of all lingering data then choose Security Option>Zero all data) when choosing a name for the drive, use the same drive name as before.
4: Quit and install 10.6, then go through setup, reboot and use the same user name as before. Software Update, install programs from fresh sources (enter any serial keys) Hold Option and click on Purchases in AppStore to redownload (not Lion of course) and then finally return user files to their respective folders on the Snow Leopard drive.
5: If you have issues with iPhoto, you can right click on the iPhoto Library and "Show Package contents" and in there is a folder with all your originals. Copy them out and delete the iPhoto Library and reboot, restart iPhoto and it should be recreated, which you can then import your copied originals again.
Note: using the same drive and user name as before, returning files exactly into their respective Music, Documents and Pictures folders like before matches any pathnames some files like iTunes has to the location of your files. If not done, then exclamation points will occur in iTunes when you click on a song. The iTunes Library will have to be opened in Text Edit and all the partial pathnames "find and replace" corrected to repair.
Optional, but recommended.
Ideally it's best to first Carbon Copy Cloner the 10.7 internal to another blank external HFS drive before doing the above steps 1-5 as that way you have a copy of everything in case you missed something or you need to hold option boot from the 10.7 clone. The clone can later be erased and used as a 10.6 clone. Or reversed cloned back onto the internal drive or as many external drives as needed. (don't boot a clone on a different Mac, you can access the files though)
Clones are hold option key bootable, TimeMachines drives are not.
Note: The above steps are ONLY for Mac's that didn't come with Lion preinstalled. For reverting a factory Lion to Snow Leopard requires other methods.
