When I noted that Sun's plans for OpenSolaris threatened the Solaris ecosystem, I got a mixed bag of comments.
Some of the comments missed the point, which is that compatibility (across the board) is a key strength, and that producing something that forces what is essentially a new platform on the world will drive away old customers without necessarily attracting new ones.
The key point is compatibility. And while modernization is essential (I'll come back to that later), it is possible to do it compatibly, in an evolutionary manner, rather than doing a rip and replace job.
Evolutionary change allows you to keep existing customers who thus have an easier migration path; makes it easier for new adopters who can tap into the existing skills pool; and allows the improvements to be fed back to older (ie. current, such as Solaris 10) releases which still have a long service life ahead of them.
Replacing the packaging system and installer from scratch is just something you should never do. It's probably cost the Solaris/OpenSolaris ecosystem about 2 years, and we can only hope that we can eventually recover in the way that Firefox did after Netscape's mistake.