I snuck a quick peek on the way out the day and, mirabile dictu, it is truly a widescreen picture. Looks quite nice.
I noticed the conversion artifacts that Scott mentions during breakfast when I was watching the Open on plain old television. I didn't see them on my brief check of the HD picture although I'd say it looks more like EDTV-ish quality than actual 1080i or, dare I hope, 720p. Clearly better than the regular TV picture, though.