Execs and seniors will be on retention bonuses. So you wont see much change for 1 yr plus. After that ... all bets are off. Your current departments will get merged into IBM. It will start with sales and support. They will be asked to eventually support the muddled IBM stack along with your products. Finance, your own IT support and admin will all be jettisoned very early on. No need for them. Then they will start messing with PM and R&D. Then the cuts come. Then you're just another part of IBM. Save yourself the misery and get out now.
Bumped from @VTljECw-ygk for info.