Do you remember the time when the Walkmans, DiscMans, or even Typewriters and blackboards were so cool? Not anymore, they got replaced, all good things must come to an end and better things in their place.
Same has to be said about the Symbian OS, and I know some will argue it's still better that what we have today, but every good thing has it's place in time/history.
The last shipment of Symbian phones will be made this summer and judging from how popular this OS is, it will take a generation before it is wiped completely off the face of the earth and stored in some phone archives musuem somewhere (presumably in Texas, don't know why I chose Texas).
I remember my first symbian phone, it was the 7650 back in 1999 and if you search on ebay today, you are going to find one for sale, if you don't you will at least find some of its accessories, batteries, casings... So while Symbian's blood supply has been cut, it will run on life support for a very very very long time.
So cheers to you Symbian, for giving us an OS with shoes so BIG that it will take a while and many many GDR updates before the Windows Phone OS can fit in your shoes.