I wonder if any people who upgrade themselves on a train also decide to upgrade on planes. I also wonder what the cabin crew would do if someone went from Virgin Economy to Upper Class.
While I know that everyone has a seat, this isn't the reason everyone upgrades. Some seem to just think they can because it's unfair that they can't, or should have to pay for something they feel entitled to.
Yes, new rolling stock may have most of the things currently, or soon, reserved for first class (Wi-Fi, sockets, seat-back screens or whatever) but you'll probably get other extras (food, drink), wider seats, more room, curtains or whatever - and the chance to do some work (which is why you, or your company, might pay the surcharge). Thus, there will still be a difference over standard and a reason to keep standard class people out.
If you feel like treating yourself, or actually have a time where you need to work (or rest) pay for a FC ticket or seek a TM and ask to upgrade. It's really that simple.
Perhaps if we get smartcard ticketing, passengers will be able to upgrade themselves without a TM/guard/RPI - and, presumably being timestamped, it will be easy to spot people who saw a guard and then rushed to the reader! The passenger is then charged £xx automatically, and then has a validated ticket to claim any benefits offered to FC users (or not, if the upgrade specifically excludes them). I can even see that regular standard class travellers might then earn points on their smartcard that would enable some free FC upgrades, but that's for another topic.
Whether you think that it should be available to everyone or not, it isn't.
