As everybody used to know, @mac.com and @hotmail.com are usually popular webmail accounts strongly related with some operating systems, which used to help on their popularity, specially from their users.
The most close of this we can get is opening a linuxmail.org webmail account, but i think would be interesting Canonical providing free webmail account, where we can, for example, use there our launchpad.net login+pwd, like we used with shipit.
it provies and maintains ubuntu, it provides a mail forwarder to your chosen mail account, which your welcome to configure to use as your main email address, so you don't need webmail to use your $firstname.lastname@example.org address, just set your outgoing mail settings.
I send mail from my ubuntu mail address on a regular basis.
I don't see why this is the responsability of ubuntu or why webmail is a limiting factor in using the ubuntu.com mail addresses.
Ow, I hate to agree with taking ideas from Microsoft and Apple, but this does seem to have some merit. Maybe if only Conanical allowed someone else to use the trademark to make a kinder, gentler webmail provider that didn't use your correspondence for marketing statistics or limit your use to certain applications and restrictive protocols.
BUT... it doesn't have to be free, Conanical could stand to make a few bucks out of reliable email provision, I'd pay for it!
Canonical could use an open source program like Roundcube (just an example). They would just need to host it and include it nicely into Ubuntu One. It should simply use the storage of the whole Ubuntu One account! That would be awesome!