Michael Weisman wrote up an informative blog post on how you can use FME with open source software and tools. The killer example here for most folks is the ability to get open source data formats and servers into ArcGIS Desktop.
The wide range of formats FME can write to can also allow you to send data into open source platforms from popular non-open source back-ends like SDE or Oracle. FDO can be used to pull data from any format into , and with FME Server you can stream live data out of any source we support into a format which is compatible with your open source client.
In addition ESRI is re-branding their ArcObjects Blog to ArcGIS Developer Blog. Personally I think it was a good decision, ArcObjects is such a small part of the ESRI Developer community and they need to continue their progress of reaching out to the masses that deal with RESTful APIs, Flex and Silverlight, Python and the JSAPIs.
Time to put that baby to REST…