I will grant that the price/performance is still a little beyond the PC market, but it fills a nice gap. Professionally, I do a lot of work on Sparc/Solaris, but use NT at home because of the cost of buying a decent Sparc workstation. This causes a lot of difficulties for me when I work at home, especially if I am writing code specifically for the Solaris platform.
For software development, it is really nice to be able to work at home without making significant sacrifices because of serious cross-platform incapabilities (such as NT vs. Solaris/Unix/Posix threads), or application sacrifices (Linux is fine for portable Unix development, except for when I am developing binary extensions to products like Oracle, which happens to be a lot of my development work).
Having a "reasonably" priced Ultrasparc available gives more freedom of choice to people who do consulting or software development at home. If nothing else, this is a move the RISC vendors should have done a long time ago.