The filing does point out the Galaxy Tab 10.1 which is also known as the GT-P7500 that sports a 3G logo. Test reports point out that the device will support GSM 850 and 1900 bands, in addition to WCDMA (UMTS) bands II and V. These are bands that are used by AT&T in the US, which more or less confirms that there is a 3G capable model of the Galaxy Tab 10.1 that will be coming your way from AT&T in the near future.
AT&T did not yet make any official mention of a release date or pricing for the Galaxy Tab 10.1, so stay tuned.