Since all current and previous iPhone (and iPod touch) devices have 802.11b/g WiFi, if placed on a faster, wider-range 802.11n network, they typically cause such networks to downgrade to 802.11b/g speeds for compatibility. This means your hyper-fast router will slow down your iMac or MacBook whenever your iPhone hits the network...
...But maybe not for much longer?
Apple Insider reports that the FCC has just been hit with new versions of the Airport Extreme (802.11n Router) and Time Capsule (802.11n Router + HD for Time Machine backup) that handle things a tad more gracefully:
The documents appear to indicate that Apple is adding a combined mode, allowing its AirPort base stations to simultaneously support iPhones and other 802.11b/g devices operating at 2.4 GHz, while also broadcasting 802.11n wide signals in the 5GHz band to maximize throughput for notebooks and devices such as Apple TV. Existing models can only run in one mode or the other, providing either wide compatibility or the highest possible network performance, but not both.
While only the most power-mad of power users will likely ditch their old Airport Extreme or Time Capsule for the latest/greatest, the new features should appeal to iPhone users looking for high-quality routers to round out their setups.
Now who wants one?