http://en.wikipedia.org/wiki/Annex_M
Wiki reckons 3.5Mbit/s is possible but Internode says a more conservative 2.5Mbit/s is more likely:
http://www.internode.on.net/adsl2/faq/annex-m.php
I see that Internode offers a big range of DSL plans - makes Telstra look sucky in comparison, but that's probably not very hard. The SoHo 24/2.5Mpbs plan looks nice...