Robert,
Yes no updates are planned for these switches, i would guess the expectation is to leave your switches into existing networks unless failure or if your business is planning on expanding;then i would look into covert existing switches over to new ones. The biggest thing is as newer browser version comes out, the browsers won't display certain feature sets and cause configuration of the switches tougher. If no big expansion/configuration is needed then you shouldn't have any problems.
Date of 2012 is the last day of phone support on these switches.
EOL/EOS link
http://www.cisco.com/en/US/prod/collateral/switches/ps5718/ps9967/end_of_life_notice_c51-632243.html
If level of support is concerning then yes it’s time to consider moving over to the new switch line.
Biggest thing is the conversion from Linksys a division of Cisco branded, now to Cisco Manufactured branded products.
New model of SRW switches (SG300 Series)
http://www.cisco.com/en/US/prod/collateral/switches/ps5718/ps10898/data_sheet_c78-610061.html
Hope this helps,
Jasbryan