Of course, it was just back in September that Broadcom provided their own open-source Linux driver that covers their latest 802.11n chipsets for the BCM4313, BCM43224, and BCM43225 ASICs by this brcm80211 driver now found in the mainline Linux 2.6.37 kernel and later. The Broadcom chipset that this Polish developer though has been working on is the BCM4328 and for the community B43 Linux driver.
His patches should be merged into the wireless-testing Git tree in the near future and the WiFi adapter's firmware needs to be extracted using the b43-fwcutter. This support is also limited to the SSB-based BCM4328 with PHY version three or lower. There is also no support for checking WPA/WEP, RX/TX collaboration, 5GHz channels, 40MHz wide channels, and MMIO tools.
The B43 and B43legacy drivers up to this point have supported Broadcom's 802.11b/g chipsets. For their 802.11g supported chipsets, there is working support for station mode, mesh networking, AP mode, ad-hoc, monitor and promisc mode, in-hardware traffic encryption/decryption, card LED support, in-hardware MAC address filtering, packet injection, etc. The B43 driver's web-page is on LinuxWireless.org.
Rafał Miłecki announced his 802.11n B43 driver work on his blog.