Agree with Raff. As an individual you can even keep Softimage in your pipeline at some degree for years until you find something better to replace that old Softimage. You only have to train yourself and you can do it while you work with SI at some degree. Or even try different solutions until you find the best one. After all you only need to care about 1 person.
As a company, you can't weak short-term solutions. You can't afford to risk the possibility of not having SI users or licenses available in the market when needed. The real problem with SI death, from a company pov (IMHO), is that you can't buy licenses anymore, so you can't increase or decrease your licenses and artists as needed. And that, plus the eventual and inevitable decrease of SI artists available is a deal breaker. Companies need to migrate their entire pipeline to something else as soon as possible. And that means re-train all your staff, increasing human error probability and decreasing exponentially efficiency. And most probably, you need look for a few Maya (or whatever you choose) specialists to help you in the process, specially if your company is almost entirely SI based. Martin