Yes, the GSM Galaxy Nexus supports 21mbps HSPA+ on 850MHz, 900MHz, 1900MHz, 1700/2100MHz (AWS) and 2100MHz (PCS). Meaning that it'll work on any GSM carrier in the world.
Both 2G and 3G on AT&T and T-Mobile, of course.
Nice thanks
And I understand it's faster also because it uses flash memory rather than an sd card?