I was seeing the same thing last night with no internet connectivity in the HD menus but it was working fine in the sd section. Called Tivo and they told me the same thing that this was happening to other and to wait a few hours after a few reboots still nothing. then before I went to bed they were back. My advice is to switch to the sd menu if you need to access hulu or netflix and wait it out. There was also another thread that gave directions and changing the tivo to a static ip address that seemed to work for some too.
good luck
http://www.tivocommunity.com/tivo-vb/showthread.php?p=8421777#post8421777
good luck
http://www.tivocommunity.com/tivo-vb/showthread.php?p=8421777#post8421777