Wireless provider AT&T remains on track for a national 3G femtocell launch before the end of 2009, according to a senior company executive speaking at a conference in London earlier this week. While a more defined date is not known, AT&T's launch will be the first UMTS-based 3G femto service in the US. The service is already being tested by some 200 users thanks to trials of 3G MicroCell home stat