I think the Streak may still be the only "phone" above 4.5 inches, although there seem to be more and more coming out in the 4.3"+ range. I believe Dell/At&t huge failure in promoting the device has scared away other makers from getting this large, although I would love a device even bigger (screen, not actual size).
It is a year old, hardware wise, operating system is 2.2 which is not bad. About 6 months ago, there was allot of talk of a Streak2 coming out in May, but I haven't seen anything new in months and doubt that Dell will come out with anything new.
I like my device, my only issue is that it doesn't like "heat". In Florida that can be a problem, but if the device overheats from sitting in a hot car or just being outside in my pocket too long, it just shuts down. Maybe that is common, I never had the same issues with my old Blackberries.