I for one will wait for the final product, no matter how long it takes.
SSMS 1 has set the bar. The existing product (ver. 1) can be played over and over. Each mission can take days to complete if you choose.
In my view, Version 2 will add the eye-candy and improved UI that we have all be craving. Other than that, I would want nothing changed as Ver. 1 makes the grade for me in mission simulation.
And don't forget, the Shuttle is gone forever. Anything we do in simulation is a recreation of history. History takes time. Be patient. If you need a change of pace while waiting on SSMS 2, look at the "freeware" space simulationr product whose name cannot be said in these forums, but it does being with an O. Exactly the same only different, and in the end you'll still be wanting your Ver 2 of SSMS.
Happy Holidays and a Happiest New Year!
-Braun (a day 1, 2007 buyer of SSMS 1