16:9 material on the XL2 is still 720X480….
The 16:9 process is handled by on-screen simulation or the hardware player.
If compressing to MPEG 2 for DVD… choose Widescreen preset so widescreen flag is applies and player shows correctly.
If going to the web.. you need to change your output size
720 X 1.2 (the widescreen Pixel Aspect Ratio is 860_
So
860 X 480
430 X 240
etc
This is covered in article on my sites…
Richard M. Harrington, PMP
Author: Photoshop CS for Nonlinear Editors, Understanding Adobe Photoshop, and ATS:iWork