@tqen That's where WP8 comes in. Upgrades don't necessarily have to be persist on the same hardware (look at Android or even BB10). Like I said, I (and millions of WP7 users and new Lumia owners) will be pretty disappointed if there wasn't an upgrade to WP8 but it's not the end of the world, and it's not going to make me switch to Android/iOS for my next phone.
Again, we'll know when the time comes. And actually, regarding the charging part, it's not that it can't be done, it's just that nobody has done it (?). I think people have already mentioned they wouldn't mind paying for an upgrade to WP8. I wouldn't too, if the price is right (although obviously free is much preferred).