If it’s not new, I didn’t notice it before. This "view as text" feature (based on their cache) is convenient since you don’t need the Acrobat plugin to read the converted files. Besides, this allows the keyword highlighting (from Google’s toolbar) to work.
11/03/01 update: Miguel Marcos tells me it’s been around for several weeks. There’s also a "view as html" option for Word, Excel and Powerpoint documents.
11/05/01 update: Google Unveils More of the Invisible Web.
03/13/02 update: now Googlebot indexes https sites too.