A second hotfix for Delphi 2010, which applies to the last update (called "Update4/5"), has been released by Embarcadero Technologies. According to the read file (see also http://edn.embarcadero.com/article/40537) the fixes included relate to:

-  the Type Library options for "SafeCall function mapping" 

-  an issue in CPP32.EXE

- an issue in DataSnap communication when using filters (in the unit DBXTransportFilter.pas)

Too bad this hasn't been extended to fix some of the annoying problems of Delphi 2010 REST support (as I was hoping), including the problems parsing of JSON with white spaces (http://qc.embarcadero.com/wc/qcmain.aspx?d=80262) and the mismanagement of Unicode strings in REST calls. Guess we'll have to wait until the next version to see those fixes, which is something I hate, considering the lack of workarounds for the second problem.