S!
IL-2 won't die when SoW is out, there are patches still to come for it, with new content, bug fixes etc. So before SoW reaches the maturity and amount of content IL-2 has now, will take a couple of years minimum. Remember that the process of creating new planes and such for SoW is a slower process than in IL-2..if your read Oleg's interviews
Until then IL-2 will still be a strong sim alongside with SoW.
If SoW will get regular updates and new content, it will for sure live for 10 years as there will be nothing to challenge it anytime soon. So we will basically have a few sims to play: RoF, SoW and IL-2 from WW1/2, DCS-series and Falcon for more modern stuff..and that is a lot during these days when sim industry is not the most popular.