The Vegas trial version will allow you to use all product features, except for export to certain formats that require third-party licensing (i.e. MPEG, MP3, and AC-3).
This is mean that I will not be able to burn a DVD (using Roxio) after rendering it?
You can't! -->Unless you already own SonicFoundry/Sony products.
I say this because for me (a VEGAS, ACID, & SoundForge user) I already have the .mpg & .mp3 plugins licensed. When I installed the trial of VEGAS 5 every option imaginable was there. I can render to .mpg or .mp3 or whatever else VEGAS offers as a rendering option with the V5 trial. I have made CD's & DVD's using the trial. I just now purchased the Full Version so I'm just waiting on it to arrive.