As far back as this MS support page goes, Visual studio editions had a 5-year mainstream support period, and since VS .NET 2003 – a 10 year extended support period. In particular, VS2010 mainstream support is advertised to end on Jul 14, 2015.
Now given that MS releases major new VS versions roughly once every 2 years, such a support period can be quite a burden. In my (much, much smaller) organization we don’t bother with backward support at all, we just ask those pesky cry-baby customers to upgrade to our latest version before we even consider checking their bug reports. The logistics of testing and patching multiple versions can admittedly get exhausting – so I would have had great respect to the magnitude of the task that DevDiv took upon themselves when they chose to support 2.5 versions backwards.
If they would have actually done so.
As of ~July 2012, the VS bug submission form in Connect no longer enables even reporting issues with VS versions prior to 2012 (note, I think that was before VS2012 even reached RTM):
For all practical purposes, support in VS2010 ended less than 2 years after its release – and less than 1 year after its first service pack release! In our organization (and I suspect in many others) we don’t even consider upgrading VS before the newest version has had its run, and reached a level of maturity attainable probably only at a service pack release. That leaves us with less than a year of practical support, which is beyond annoying – it borders on fraud.
I should probably post here more details about specific unresolved bugs I reported. Beyond that and the much needed venting, I don’t see much that can be done.