Looks like Boxnation will be launching either on the 30th of November / 01st of December just in time for Cotto Vs. Margarito II. This page on their website was just updated today.
http://www.boxnation.tv/subscribe.php
"By registering now, you’re not committing to anything. You will simply receive news from BoxNation and information on how to subscribe to the channel ahead of the subscription service’s launch on the first of December.
Sky customers will soon be able to subscribe and pay for the channel through this site, while Virgin Media customers should contact Virgin directly (we expect to be live on Virgin Media cable within two weeks)."