I have playing around with trying to get the TTS speedcams to work on WinCE version and I have finally managed to get this working. Attached are the files that you need to put in the correct folders and the speedcams and other TTS messages with work. I am using Loquendo TTS engine and hence modified the voice for this engine. Put tts-speedcam-eng.zip, speedcam.zip and ttspro.zip in ux folder and Voice_TTS-Loquendo7-Pro-UK-Kate-zervdim.zip in the voice folder.
Once these are in the correct place the speedcams and other TTS messages will work, you can test this from Test TTS menu option.