I whole heartedly support moving forward on SASLv2. It has to be done at some point, and the sooner some momentum is generated, the sooner other groups (sendmail, OpenLDAP have been mentioned) whille make the transition.
Regarding complaints from those who don't want to mess with different software systems using different versions of SASL... DONT! Immediate upgrades to the latest version are not compulsory. How many recent messages start with "I'm running Cyrus 1.6.x on ...". If you have to wait for sendmail and OpenLDAP to catch up, don't worry, they will. If there are any compelling, non SASL updates in 2.1 that you just must have, I'm sure they can be back ported to 2.0.x. As far as I'm concerned, the improvements of SASLv2 ARE the compelling reason to upgrade. Cheers Chris