@DerAlbert just pointed me at an article in German, which links to a PDF file with release notes for a recent pre-release Snow Leopard version. What it says is that a 64 bit kernel will not be used by default in Snow Leopard — in spite of all the advertising Apple has done for the 64 bit focus of Mac OS X 10.6.
Although this information is about pre-release software (and yes, it shouldn’t be out there at all — somebody must have broken their NDA), it doesn’t seem likely that things will change before the final release (which according to Apple has been in the post on its way to my house since yesterday — not here yet though).
The release notes show a list of machines where the use of the 64 bit kernel can be forced during startup, and it seems that my Mac Pro is among those. So I’ll have a chance to test this, which is nice — certainly much more than Microsoft can claim for their own efforts at supporting 64 bit.
Something I like about my Macs: Apple tries hard to deliver me everything that’s reasonably part of the operating system I bought in one package. Cool.