So what's this going to mean for scribd? Are they going to go way of the YC startup web 2.0 calendar that ebayed themselves off, after Google Calendar came out?

Even worse, they are going the way of a company built around a feature. Kiko users would have had to consciously move to Google Calendar. With PDF viewing most people won't even notice if what they are using changed. (I'm not ranting against Scribd - the same applies to others, like YouTube, which are essentially viewers for data that's hard to view.)

Scribd's approach of being a destination website is completely broken IMHO, because the Web already has a destination to read any type of text - the Web itself. What they should've had is a Firefox plugin that captures my PDF links and opens them in Scribd instead of Adobe Reader. Google is doing this for mail and I'm sure a feature like that is in the plans for Google Toolbar.

This is a completely different thing than Scribd.

Scribd is a document uploading and management service that converts .pdfs, .docs, .xls, everything under the sun.

This is an extremely nice way to view PDFs linked to from google search and gmail.

It doesn't seem completely different.

Scribd: Upload a document, make it visible to anyone Gmail: Email a document, make it visible to anyone (that you explicitly name)

Scribd: Converts pdf, doc, xls, lots of stuff Gmail: Converts pdf, doc, supports any file type (the recipient may need software for it)

Seems to me like both are squarely aimed at the "sharing documents" market.

Scribd is all about turning documents into public URLs.

The new google service is about sending documents to people or small groups.