Starting some time within the last few days (appx. 8/31/10) drafts created within the Gmail web interface (whether on your PC/Mac or using the browser on your Android device) are no longer being pushed to the Drafts label within the Gmail app on your Android device !!!
This is a major issue !
See the following thread:
Drafts created and saved in Gmail on PC (using Chrome) no longer appear within Drafts (label) in Gmail app on Droid X - Google Mobile Help
Please add comments there and star this issue so that Google addresses this ASAP !