I would not dare to give any guarantees.
The recent raw support versions were updates to the versions of Aperture and iPhoto, that had been released for the current MacOS X:
See for example the release notes for the latest Raw Support: http://support.apple.com/kb/DL1706
System Requirements
Mac OS X 10.8.5 or later
Mac OS X 10.9 or later
And look at the Mavericks Raw Support page: http://support.apple.com/kb/HT5955
* Aperture version 3.4.5 or later, or iPhoto version 9.4.3 or later, is required to install this update.
With Lion you will definitely be left out from new raw supports.
And I am no longer sure about Aperture 3.4.5 either. Aperture 3.3. worked well with Lion, but you need to check on the Support page, when the Maintainance is over, which Aperture 3.4 version will work with Lion.
Right now I cannot reach the Apple Server - the Downloads page is unresponsive: http://support.apple.com/downloads/#Aperture