There are 1,619 API calls that folks have reported that are either flagged with a [MonoTODO] attribute or are not implemented in Mono yet.
The list was compiled out of the 244 Moma submissions available as of 8pm.
A lot of these are 2.0 calls. The API lists are available here:
I will be updating those urls with API updates as we move along.
Posted on 28 Nov 2006