Neither the disappearance of Dixons nor the demise of Comet spell the end of electrical goods being sold on the high street. Apple seems to be doing OK, doesn't it?
What we're seeing is an age where informed consumers are choosing where to take their business. I buy a lot of electrical goods, but used to hate the purchasing experience. Going into a Comet meant you had to endure a grimy warehouse with nylon carpet and endless queues. Dixons used to mean being pounced on by a gang of sales 'assistants' trying to flog you a four-year guarantee that cost the same as the product.
(One instance of upselling of anti-virus software I once overheard in PC World - for a computer that already had it bundled and installed - forced me to call over a manager to complain on behalf of the elderly stranger on the wrong end of the con.)
According to friends I have that worked in Apple stores, the devices are treated with as much respect as the customers. When a device launches they arrive at the store the day before but stay in sealed creates before the staff are allowed to open them on launch day. Every time I've bought something from an Apple store I've had a great time, and the employee serving me seemed genuinely thrilled. (This might just be training, but I don't care.)
High-street shops need to realise that the internet isn't a threat to their sales - it's creating a generation of consumers who already know what they want before they walk through the door. But they are still going to walk through the door.
Learning to respect both the devices and the new consumer will keep those doors from having to be shut for good.