Steffen: _mac_ver_xml should not be dropped, it is a perfectly fine way to determine the system version.  Discussing it is also off-topic for this issue, please keep the discussion focussed.

Wrt. mailing Apple: I wouldn't expect and answer. Is there something specific you want to know? I'm currently at WWDC and might be able to ask the question at one of the labs (where Apple's engineers hang out).

If it is really necessary to check for the OS version to enable the OSX-specific bugfix it is possible to look at the uname information instead of using gestalt.  In particular something simular to this Python code:

   v = os.uname()[2]
   major = int(v.split('.')[0])
   if major <= 10:
      # We're on OSX 10.6 or earlier
      enableWorkaround()

This tests the kernel version instead of the system version, but until now the major version of the kernel has increased with every major release of the OS and I have no reason to suspect that Lion will be any different.

BTW2: OSX 10.7 is not released yet and should not be discussed in public fora, as you should know if you have legal access.