How long does it take to Install Ubuntu on the Nexus 7 ? Is it normal for the screen to be black during power on? I don't see an Ubuntu logo. Is that expected?
The installer has several steps that can take quite a long time (up to about 15 minutes). The installer may be working as expected in these cases. The last phase in particular, after the bits have been copied. The device sits for awhile without indicating progress, please be patient during this step.
The screen is black during bootup because Plymouth is disabled in the build due to this bug. With Plymouth specific to the Tegra3 platform.