Sun has canceled the UltraSPARC IIIi+ (Serrano) processor series. This move was done to better focus on the UltraSPARC T1 (Nigara), Niagara 2, and the UltraSPARC IV+.

"We canceled it last fiscal year to focus on the ramp (up) of UltraSparc IV+, Niagara and Niagara 2," he said. "The big push in the volume area is Niagara 2," he said, referring to lower-end machines that sell in high volumes.
http://news.com.com/Sun+scraps+low-e...3-6111456.html

The UltraSPARC IV+ is expected to be able to run 64 threads, so things should certainly get interesting. There are also those rumors about Apple + Sun.