Not at all. The beauty of KVM on SmartOS is that Joyent's customers can run BSD, or Linux, or Windows, or whatever they want without even knowing it's running on top of Illumos. That's why the user base isn't as much an issue. But the underlying foundation is critical. I'm actually really glad BSD is adopting DTrace and I'm sure it will be successful, but the BSD documentation says that it's experimental and not yet production ready (http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/dt...). Solaris DTrace has been in production since at least 2005.

Disclaimer: I work for Joyent, but I do not speak for them.