The article doesn't describe SNI at all. With SNI, you can deploy multiple certificates on the same IP address. The method described here uses a single certificate that includes multiple domains in the subjectAltName.

Obviously, SNI is the superior solution for a shared hosting environment. The approach described in the article is fine for consolidating some related domains into one certificate, but would be an expensive management headache for many unrelated domains.

You are right, I was sure that the title was "Multiple-certificates...", not "Multiple-domain UCC certificate".

That's what I get for not reading the whole thing, sorry.

Yes it does. The page in question describes setting up a certificate with multiple names. This works fine for XP and doesn't need SNI.