Well, I was very excited to see both free POP3 & Forwarding in GMail, as this now allows me to fully utilize my GMail email address...
It occured to me, however, that with 2GB of storage (and counting),
AND IMAP access, it would make using GMail the absolute solution... You see, using both POP email and web based email doesn't work real well for many reasons, as the two store everything seperately... So say you download all you email though POP, then read half of it, but leave the other half in your POP client unread. When you log into GMail later on, you will either end up with all the email being marked unread in the inbox, or all of it being marked read & archived. When you are talking about, say, a months worth of email, you could have to re-sort out hundreds of messages when you get back to the web interface... Plus if you, say, sort out your email manually into folders (which I do) in your POP Client, then go to web mail, NO sorting has been done!!! When you talk about hundreds, or maybe even thousands of email messages, sorting everything twice is far from a reasonable experience...
IMAP however is much different, as you can setup your client to basically organize everything ON the email server. You basically would (or could at least) leave ALL your email on GMail's server, organize and access it FROM GMail... So when you do log into web mail, all your email is sorted marked read/unread, flagged, etc. exactly as it was done in your client! This would be ideal, as it would give you all the access of your POP Client (assuming it's IMAP compatible), and the full ability to go into the web mail interface and get exactly the same organization...
As of now i'm using the forwarding feature, as this is the easiest way to get my GMail in the same place as the rest of my mail. This, however, does NOT give me the ability to access all my email on any other machine but my main system... I am glad that they have this ability, but if they added IMAP, I WOULD use GMail as my primary email server...