Engadget reports that the Samsung GT-S8500 is the first phone to support Bluetooth 3.0. A look at the Wi-Fi Alliance website reveals that it was also the first feature phone to gain 802.11n certification.
The certificate is dated December 28th 2009, the same date that the first smartphone was certified for 802.11n – the LG Veri/VS750. The VS750 Wi-Fi appears to be more advanced than the Samsung, since it is certified for short guard interval and WMM Power Save.
While these are the first phones to gain Wi-Fi certification for 802.11n, they may not be the first to market.