I've finished the switch over to Gmail from Eudora, and I think I'm in Gmail to stay.
There are definitely some big advantages to Gmail over Eudora.
--Easy tagging and filtering of items (Goodbye, Mailboxes!--I had over 100 of them)
--Conversations are threaded and present as one item in your inBox
--For those of us who are not always working in the same place, you carry your inbox (and archive) with you.
A few drawbacks:
--No (or very limited) emoticons :(
--Some messages seem to lag in getting to me (altho I'm not sure why)
The Message Uploader that I linked to in my previous post didn't work well---I had to leave my archive behind in Eudora and refer to it as needed.
All of this was a timely switch given the talk this week in the Libraries on 'The Googlization of Library Services.'
Some other drawbacks (I made the switch a little while ago to gmail for my 5 accounts):
no multiple signatures without using weird scripts
no folders!!!
sending attachments file size is more limited than Eudora or webmail
great system, just hope it continues to improve!