This lists a 533mhz system bus which does appear to be Sonoma. The old system busses of the Centrino 2nd revision (Sonoma is 3rd) was 400mhz.
You have a full Dothan Pentium M processor with 2mb L2 system cache but it should be identified as the 730 1.6 Pentium not the 725 (old builds end with 5, Sonoma builds end with 0) so confirm that./
Also, the old RAM was mostly PC2700 (333mhz) and now the RAM is supposed to be faster than that also.
Also, the wi-fi card should have a, b and g -- the old wi-fi cards were 54g/b only (Intel 2200b/g or equivalent).
See the Dell 6000 specs on their website to compare as this has been identified and released as a brand new Sonoma Pentium M model (not upgraded -- released just a few days ago)