In going through and converting my external tools, I stumbled across this problem. A few of my tools used a CategoryFilter on the category ‘BuiltInCategory.OST_DrawingSheets’, this was so I could get all of the sheets in the revit model. It appears this is not a category anymore.
A scroll through the categories revealed another category ‘BuiltInCategory.OST_Sheets’, that appears to achieve the same results.
I plan to continue posting any little changes like this that I’ve noticed in my Revit 2010 conversions.