I can see send file in web version of GTalk on Google+ but not in GMail.
Is that new?

https://plus.google.com/114763003787914218110/posts/L4yoqXQW9Rg

Nope, it's also available in iGoogle and orkut but not in Gmail.
http://googlesystem.blogspot.com/2010/03/send-files-in-google-chat.html

Ah, and it's old!

Thanks :-)