Stop-sign after boot and "Still waiting for root device" Need some advice regarding a problem starting up my Mac Mini (mid 2011). 

The other day I was browsing websites when the machine froze with the spinning beachball. So I was forced to power off/on my machine. 

The machine started and showed Apple logo with spinning wheel as usual. But then the logo turned into a stop / prohitbited sign (a circle with crossing line). And everything stucked there.

I try other options several times by booting with:


Shift pressed (safe boot) - Apple logo appears then changes to stop-sign as before
Option pressed - Gray screen, nothing happens
Cmd-R - Gray screen, nothing happens
Cmd-Opt-R - Gray screen, nothing happens
Cmd-Opt-P-R - Double 'Ding' sounds but nothing happens.
Cmd-s or Cmd-v - This switches to black screen and show the text in my attached image. The most notable thing was the repeated message 'Still waiting for root device'


All my search results are telling this is a harddrive problem. Is there anyway I can confirm this? I have an external CD/DVD drive but not the Lion installation media ..

Luckily machine is still under 1 year warranty, but losing all the data in my drive wil be a great pain .. 

Thanks!
Apparently some important System Files got corrupted somehow. Although unable to boot, your data should still there.

You could retrieve your data by connecting your Mac Mini to another computer by FireWire. To do so just:


Connect the computers with the FireWire cable.
Boot your Mac Mini holding down T.
The Mac Mini's HD will be mounted as an external HD in the non-corrupted computer. 
Find and save your valuable data.


Afterwards, making a Clean Install is the usual and fastest way of solving this issue.

I guess you can get this done for you in the Apple Store, though. Even more, if the machine stills under warranty.