I went back to the 35-minute demo and took a look, since that's the only time we've ever had a glimpse of the inventory. Bearing in mind that the inventory is (according to previews) now different from back then (since it was a work-in-progress), I did notice that the version in the 35-minute demo had absolutely no indications of durability/degradation status. See below for one of the many swords that were briefly on display. This could have changed by now though.
EDIT: I somehow managed to miss the big hammer symbol. That's probably durability. Uh.
As for the hassle of repairing swords, I doubt CDPR are - for lack of a better word - stupid. Most features appear to have been thoroughly thought about before being implemented, all with the goal of bettering gameplay. Example: skill tree slots to increase the need for preparation before fighting. Of course, everyone has different preferences so every feature will be debatably fun or not, but my point is I'm sure CDPR has thought through their implemented features carefully and have good reasons for giving them the green light. Allow me, then, to speculate on the likeliest reasons for weapon degradation.
Weapon degradation is a gold sink. The Witcher 3 will span at least one hundred hours of gameplay, and some form of monetary loss is necessary to ensure nobody gets filthy rich twenty-five hours in. How much of a gold sink depends on CDPR. It could be a hefty sum for each repair, in which case durability must be high to spread out repairs. Conversely if it's a small sum for each repair, durability might not be so high. However, I'm willing to bet it's not a hefty sum. But this does not mean durability will be low. If weapon degradation acts as a gold sink for Geralt, it makes sense for other elements in the game to do so too - one of which is likely alchemy. I'm going to assume alcohol isn't lying in wait every twenty metres, waiting for Geralt to loot loot loot. One must likely buy alcohol and pretty often too, given the necessity of potions (let's not drag the supposed evil of no herb gathering into this though). The purchase of alcohol, in combination with gold paid for weapon degradation, means a nice gold sink without needing to decrease durability to compensate for small repair costs.
Of course, even if this logic is correct, the game must still be balanced to ensure we're not losing far too much or too little money, and that we don't have to make trips to the blacksmith too often. If we can chop through a decent number of monsters with our swords intact, then I think it'll be fine.
Additionally, repairs can possibly add to the idea of preparation before facing a boss. Swords are after all still functional if you choose to neglect repairing them; it'd just take longer to kill the Nekkers you bump into (therefore also increasing your chances of dying thanks to said Nekker, but that's your risk). But if you know you're going up against the Leshen and his posse, you'd be buying all the alcohol you can to brew all the potions you can, and you'd purposefully make a trip to the blacksmith to get your baby in tip-top shape before heading into the woods. The poor blacksmith gets some extra income too, instead of just wasting his pension on the junk you're selling and scrambling for your gold during the odd weapon forging. Once again though, it's a matter of how CDPR balances it.
Well that turned out longer than I intended. But if I were to sum it all up, all I can say is I think we currently know far too little to make a definitive judgement on whether the system is good or is the greatest abomination CDPR has ever birthed, just like the alchemy system. We simply won't be able to until we actually play and experience the system ourselves. For now, I choose to believe CDPR have thought very carefully about all the features they've implemented and come to the conclusion that these are their best possible incarnations. Whether this turns out true or not, come May 19 we'll know.
