Even though HD DVD burners are still off in the distance, you can make a DVD that will play back 720p or 1080i content on your HD-A1 or HD-XA1 with your existing DVD-Rs. The guys over at AVSForum have been working on this since the the Toshiba HD-A1 player launched, and they've pretty much got it down to a science. Particularly given the lack of content available so far on the format, many people have .ts files, HDV content, or mariposaHD episodes they'd love to play back from a single shiny platter. They've boiled the process down to a few steps that anyone familiar with DVD burning should be able to follow.
Basic Steps for Creating HD DVDs:
1. Capture a high definition MPEG2 video to your computer.
2. Convert the video file from .ts, .tp or .m2t transport stream format to program stream format using Womble MPEG2VCR.
3. Create an HD DVD folder on your computer using Ulead Movie Factory 5.
4. Burn the HD DVD disc using Nero Burning ROM.
For more details and list of necessary software check out the thread, currently this walkthrough is PC-only, although WiFiSpy also notes he is working on a Mac version so that shouldn't be too far off. With a guide like this, all you need is a DVD-R, a sharpie and a Qosmio laptop to recreate the Sony Blu-ray incident. Or you can take that old rip of The Fifth Element you've got laying around and see if you can do a better job at a lower bitrate. The possibilities are endless.
[Thanks for the tip WiFiSpy!]