Should admin tool depend on 9.1, or stick with 8.2?

[jrusoff at apple.com]

Apple is looking at writing some frontend tools for DNS admin.  
Realistically, we probably can't support both 8.2 and 9.1, so we are 
wondering if it is sensible to move forward and build the tool to work 
with 9.1, or to stay with 8.x.  My guess is that most people are 
reluctant to migrate to Bind 9 because of database migration headaches. 
Are there other performance or compatibility issues that folks see 
holding back the widespread use of Bind 9?
Thanks for the info,
Jason Rusoff