The opposite actually, the newer KVM stuff for example will not run on older processors, Intel Core iX and very new model Xeon's are required with EPT support.
Many people, my self included, are using Solaris mainly for big storage where the safety of data comes first and foremost. There is still not good competitor to ZFS that works as well and provides the same gaurantees.
Honestly, more and more people with big data problems are turning back to solaris kernels over linux because of how many issues there are with linux when you are really running it hard. ZFS, dtrace, and the Solaris kernel on new hardware is really a compelling argument over Linux.
I hate to be the one asking for a citation but can you share some examples of "more people" who have moved from Linux back to Solaris? I agree about excellence of Dtrace and ZFS but I'm just curious about your kernel comment.