Well I just plain think it sucks
Its a half assed solution.
"Our old system is bad... we will throw it away and start something completely new" Imagine your phonecompany doing that. "All old phones will stop working in 2 weeks... new system will be implemented. You all have to buy new phones now". WTF!
I know every company has to evolve and to implement new things. But that doesn't justify taking the old system down. If those GIM sites are so bad, fix them! Make them good. And why are they bad in the first place I could ask??
As far as I see it... this is quite unproffesional behaviour.