Newbie Q: can i jailbreak?

Hi sorry for Newb question but, since I have ATV 2 with 4.0 firmware: it is os 4.1 i believe. can i still jailbreak not having updated to 4.2? or iTunes will not allow it at the moment with current Pwnage tool .ispw created ?

If you haven’t updated your ATV to the new firmware I believe you can…check the installation section of atv2 flash…
Check this post … http://forum.firecore.com/topic/3418
Check this also… http://m.youtube.com/index?desktop_uri=%2F&gl=US#/watch?xl=xl_blazer&v=HCb_lWyfFgg

itunes constantly is unable to write custom .ispw, as it says Build not eligible for device,

I tried different hosts to redirect its "apple authorization" but nothing works. Is there another way or we got to wait?

try this 

 

http://www.fileserve.com/file/4TMxHGt/AppleTV iOS4_1_Custom_ipsw.zip

but put your apple tv in dfu before hitting shift restore or alt restore.