It’s probably already widely known, but I though I might mention it once more.

AVM currently offers the international edition of the FRITZ!Box Fon WLAN 7270 with support for ADSL Annex A and Annex B in one single box. So you don’t have to buy an other Fritz!Box when you change your phone line from analog to ISDN or vice-versa. Unfortunately the GUI seems to be only in English, all the fancy features like WLAN 802.11n (300 Mbit/s), DECT-GAP Base Station and SIP Registrar server should however outweight this limitation.