Given their installed based, they will be around for a long time.
But they will fall, just like the rest of the big Unix vendors.
Given the choice between being locked in to a single vendor,
and the illusion of multiple Linux vendors, it is a no brainer
for a CTO to choose Linux on x86 over Solaris on x86.
The Sun techs might be unhappy, but imagine if they are
give the choice: Linux or Windows?
They will fully support the Linux in that scenario.
Well, maybe not fully, maybe there will be problems, but
they will play the hero and save the day, if they have a
possible windows migration hanging over their heads.
If they are already a Sun shop, I'll bet they still dabble
in Linux for education and edge / compute / samba boxes.
Which gives them choices in the future. Single vendor
lockin is the ultimate sin for a CTO.