I am a satisfied user of gmail too and as it stands agree with the detailed analysis done by kushaaal. I believe that in today’s ever-increasing competition times, one needs to get a real edge to get ahead in competition.
While other (free) e-mail providers were adding value to their services, google really cracked it hard and quite unexpectedly a company known for web-searching’ (I was one of the few who started using them for searches much later) seems to lead a new route of dominating. I realise its early to say this because they are still in Beta version, but at the same time I don’t see any reason why they cannot rule the future of e-mailing.
I liked many aspects of gmail, but particularly liked the display history for each e-mail recepient. It definitely reduces a lot of time previously spent on searching past contents.
Some kind of linked chat potential would be great to have, though they say they don not say that’s their intention in the near future.