In fact, this Draft 2.0 certification program was created to address concerns just like yours. Consumers can purchase Draft 2.0-certified Wi-Fi products (routers, cards, printers, media centers, etc.) with greater confidence. (You can view this list of certified Wi-Fi products.)
Most analysts (including me) believe that Draft 2.0 is sufficiently mature to pose little risk of incompatibility with products based on the final 802.11n standard (to be ratified sometime next year). Although there are no guarantees until ratification occurs, any Draft 2.0-certified product you buy today will probably require only firmware and software upgrades to align with the final standard.
The bottom line: Most consumers can get improvements in speed and reliability by upgrading to 802.11n Draft 2.0 today. Personally, I would not consider buying a wireless card for my laptop today unless it was Draft 2.0-certified. Furthermore, I recommend buying only dual-band Draft 2.0-certified adapters so that you'll have the freedom to use the "cleaner" channels in the 5 GHz band. Just look for 2.4 and 5 GHz on the package (or text indicating the product is backwards compatible with 802.11a as well as 802.11b/g. However, businesses that need additional capacity and 200+ Mbps of application throughput may prefer to wait for final 802.11n products that will offer advanced 802.11n features like 4x4 MIMO and transmit beamforming.
This was first published in March 2009