Apple’s (AAPL) market share slipped slightly last month to 6.55%, according to a new report from Net Applications, while Microsoft’s (MSFT) Windows Vista picked up more than half a percentage point to 7.91% — a growth rate month-to-month of more than 7%.

The Web metrics firm’s monthly tabulations of browser data from the sites of its 40,000 customers offer an imperfect but consistent measure of market share trends. The company’s latest findings are summarized in the table below:

Net Applications offered no analysis of the data, although it’s probably fair to speculate that the small dip in Mac market share reflects buyers holding out for the Oct. 26 release of Leopard.

Charles Jade at Ars Technica’s
Infinite Loop
points out that this is the first Net Applications report in which Intel Macs overtook PPC Macs. “The transition is over!” he writes.