HP have launched their new E-MSM460 and 466 along with their E-MSM430. They are probably the first key vendor to market with a 3x3:3 access point giving 450Mbps potential.
The E-MSM430 is only 2 spatial streams meaning 300Mbps but the E-MSM460 and 466 support 3 spatial streams. The E-MSM460 has integrated antennas while on the E-MSM466 you will need to buy the antennas seperatly.
This I am sure will be the first of many cmpeting products and with Intel providing the Intel Centrino Ultimate-N 6300 wireless adapter with 3x3 support its only a matter of time before we start seeing major deployments at 450Mbps.