Cisco has announced the End of Life roadmaps for the 2960, 3560 and 3750 models of Catalyst switches.  End of support does depend upon the specific product number of each switch, but all of these models will no longer be supported by Cisco within the next 12-30 months.

End-of-Sale and End-of-Life Announcement for the Cisco Catalyst 2960 Series Switches.

End-of-Sale and End-of-Life Announcement for the Cisco Catalyst 3750G, 3560G, 3750-E, and 3560-E Series Switches