Glad I don't work there!
The company I work for also has a lot of long-service employees, who would definitely be affected if the company opened up voluntary redundancy and then pulled it back. The thing about our workplace is that it's very easy to let yourself get settled into a nice quiet corner as you build up tenure. If you aren't keeping up, especially if you've been around forever and are expensive, you get tossed at the next bloodletting interval. People who keep up get to stay for the most part. It's the nature of the business...as you gain experience you get better and build up your industry connections, making you more useful. Sometimes there are capricious firings, offshoring attempts, etc...but usually they're fads that don't last beyond one CIO iteration. IBM seems hell-bent on removing any sort of labor cost from their books lately. Just a couple decades ago, I remember IBM, AT&T, GE and others being very paternal corporations that essentially offered lifetime employment...no more I guess!
It's interesting that IBM does appear to recognize that they can't offshore everything to the cheapest rent-a-coder or rent-a-sysadmin shop, and are keeping some people from leaving voluntarily with a package. But I can't imagine how bad employee morale is there...if you're good, you're basically surrounded by everyone who hasn't been able to pull the trigger on leaving...and who is probably going to have a hard time finding a similar job.