Get it while its hot.
And for those that have not bought it yet, with this update the price point has been changed to 99p to be inline with the Ubuntu paid image.
You can have both Ubuntu and Backtrack on your sdcard at the same time (so long as you have the free space) so if you fancy trying a different linux distro get it while its hot!
https://market.android.com/details?id=com.zpwebsites.backtrackinstallguide