Not directly, no. However, the documentation states that you can use CloudTrail to log the requests from SQS to S3, then have changes to S3 trigger the events that can get your Lambda function to respond.

It's a little convoluted, but that seems to be the way they're going for now.

Currently the only services supported are S3, DynamoDB, and Kinesis. Seems like a no-brainer that they'll be adding other services though.

As of today, no. Probably coming in the future though. I got the impression that eventually all Aws services will emit events.

After reading the description of AWS Lambda, I expected SQS to be first in the list of event sources. Huh.

Wouldn't that be kind of unnecessary, when it's not too tough to write an SQS-reactive client?

Starting with S3 fills a gap as there is AFAIK otherwise no way to start processing based on changes to S3, without writing a rather wasteful program to list the resources, maintain state, and hunt for differences.

But if you have an SQS reactive client it would sit in EC2. With a service like Lambda, they are promising millisecond based pricing. A very ambitious project by them.