Denon's a fine example.  They released a receiver and a preamp four years ago that still stand the test of time in audio quality, but are a bit lacking when it comes to modern features.  This October, Denon will be giving owners access to a hardware and firmware update.

Both the AVR-5308CI A/V receiver and AVP-A1HDCI preamplifier will be upgraded to offer full 3D pass-through and Audyssey features like MultiEQ XT32, and DSX.  Dolby PLIIz will be added as well.

Pricing for the update has not yet been announced.  If you're looking for more information or just want to be emailed when the update program goes live, you can sign up directly through Denon.