Should search engines such as Google be served text/html?

text/html in contrast to application/xhtml+xml?

[JAB Creations]

I am assuming that the answer is yes but I have not seen any mention of html mimetypes on the search engine FAQ pages. Here is the post I am using to also go off of here...

[webmasterworld.com...]

So what I have devised is a filter or popular spiders along with the generic terms that proper spiders should always include in their UA to serve text/html mimetype to spiders and the correct mimetype to humans.

Comments and suggestions would be highly appreciated.

John