if you have an i5 4690k i think you should not upgrade to skylake model.. you should upgrade if there is any new processor have a base clock of 4.2ghz~4.4ghz... cause i5 over clock can easily hit 4.2~4.4 ghz... unless you have the budget to do it.
I would say that unless you plan on playing games at settings more than high settings, I would stick with the i5 that you have as it is a pretty capable cpu. But as always, you can't be sure until the cpu's are actually released and been tested.
if you have an i5 4690k i think you should not upgrade to skylake model.. you should upgrade if there is any new processor have a base clock of 4.2ghz~4.4ghz... cause i5 over clock can easily hit 4.2~4.4 ghz... unless you have the budget to do it.