I suspect this is expected behavior but I'd like verification. FileMaker's help article on the new window options in 12 doesn't mention this (perhaps it is mentioned elsewhere in the FMP12 documentation?).
I've not run into this need before but I now have a client who wants to grab the notes field which is in a modal window and paste that in another table/field. Seems odd to me that data can be added, edited, and deleted but not cut, copied, and/or pasted.