Surely Samsung will get a bad reputation with the carriers as well? Smartphones are almost always sold on a contract, so people are stuck with the same phone for at least 18 months. If Samsung aren't willing to support the phone for that long surely the networks themselves will stop using them also?
How much work does it take to update the version of android? Would the work towards the Spica make the Galaxy update easier? Maybe they might surprise us with an update if it's not too much extra work (wishful thinking there).