What format do you mean?

If you need CSV for Excel, you are better off with generating it directly from your data source.
The same applies to iCal for Outlook (you can take a look at DDay.iCal library).

If you mean exporting the graphic output, that's difficult. You need to use a browser (IE or Mozilla) programmatically to render it and than capture the output. Some attempts to achieve this can be found on the Internet. I've tried it myself in a different context some time ago and it was not a reliable solution.

Another option would be to include the PNG/JPG export natively but the questions is: What is it good for? If you have an interesting and relevant use case it wouldn't be impossible.

Yes, to generate a calendar for printing (without all the problems with IE and Firefox with strange printing).

I could try tweaking the HTML to make the output look better after printing. But this might be more difficult than producing a clean PNG from scratch. I would like to take a look at it, but it won't be before 4.4 release.

I would be interested for a PNG, maybe a next feature :)

Very good control !