Symbian actually originated from Psion's PDA OS (EPOC). I owned various PDAs from the company and have to say at the time the software was way more advanced than it's competitors (whose hardware were usually "better"). It even had it's own version of BASIC.

I think EPOC was sold to Nokia & Sony Ericcson and became Symbian?

The one stand-out feature of Symbian is that it requires modest hardware to run and is ideal for "budget" handsets.

My wife owns a "Music Xpress 5800" and she is very happy with it - that was a year and a half ago. But she wants something a little more powerful. She says she wants a "proper" web browser, more apps and a "faster" device so she is thinking of an android phone.

The problem is there is an overlap now between Symbian and a smartphone OS like maemo or meego. Users demanding more from the software means more powerful devices have to be manufactured. This raises the question of why install Symbian when the device can quite happily run a linux-based OS with all the flexibility that comes with it.

Nokia's stratagy is fine
1) keep selling your "bread & butter" devices - cheap to make and software maintanence is low. Sell these at high volume - perfect for Symbian.

2) compete in the high-end smartphone market - feature-rich hardware and OS is flexible enough for power users. May not be as high-volume but make more money per device. Perfect for Linux-based OS

If you want a high end phone then buy the N8.

If you want a high end device then wait for meego-based device or buy something like android.