Just accidentally I discovered this weird behaviour (I consider it a bug).
Open 16 bit audio file (WAV) and apply (render) any 32 bit supported plugin (like StereoExpander) => the processed audio (or selection only) should be 32 bit (or whatever the plugin outputs e.g. whatever WL shows in Bitmeter when used in realtime) however it is only 16 bit (in WL6 it is 32 bit as it should be). Happens both in 32 and 64 bit version of WL7.
The workaround I found out is to save the 16 bit audio file as 32 bit first and then apply the plugin -> only then the processed audio is 32 bit as expected.
"Create 32 bit float temporary files" is selected in Audio File editing preferences -> File.
Win7 x64 SP1, Intel Core i7-2600K 3,4 GHz, 16 GB RAM, Gigabyte GA-P67A-UD4-B3, RME Fireface 400, MIDISport 4x4, ATI Radeon HD 5750 + 2x HP ZR2440w displays
Cubase 6.5.5 WaveLab 8.0.3, HALion 5