This was one of the downsides of an otherwise great deal for the first 1GHZ Android. A lot of people was in an uproar when they found out that Google would impose an ETF in the amount of $350 if you canceled your T-mobile service within the first 120 days.
Apparently the FCC has been investigating this and most likely that asked Google to lower this fee and they agreed. The new lower ETF will attract more buyers to Nexus. This coupled with the upcoming car dock will further aid in the increase of sales of the Nexus One.[via phandroid]