I've asked around and found out that there are some companies
that may be interested in integrating Flex into their tools but
there’s nothing specific to point to. ColdFusion has some
reporting capabilities that might fit the bill.
ColdFusion, assuming you're using it, has an excellent report
engine. The report builder is also a free download. It supports
each of the formats you've described and reports can be invoked
from your Flex app with a simple link to a web page containing the
"cfr" file (or a variety of other ways).
Allegedly, if you need to do more complex reporting (multiple
nested sub-reports, for example), an enterprise class tool like
Crystal might be more appropriate. I find Crystal a bit cumbersome
and it will be FAR more expensive than CF's report builder. I've
used the CF report writer since its release (about two years
now???) and I've yet to encounter a reporting requirement it
couldn't handle. Sure it misbehaves sometimes and is a little
buggy, but I think it gets a lot of bad press it doesn't deserve.
And you can't beat the price if you're a CF user!