I fully expect that the developers didn't test it fully...because they can't...I am part of a testing team for another game that is similiar to Skyrim and our internal team of 40 find less than 5% of the bugs even though we play it non-stop...its the mass public and the demo feedback (its a PC game I work on) that help us massively...the sheer amount of variables meaning no save is alike means there are millions upon millions of permutations means you cannot fully test everything...
No, you can't test everything obviously, but the number of permutations in the case of a game on a PS3 (standardized hardware) should be way lower than for PC (different hardware, different versions of hardware drivers), which means that more bugs should be found before release on PS3 than on PC.
The difference on a PS3 lies basically in "how the game is played" and with games like these (sandbox open world games), things should perhaps be a bit better designed so that freakish things just can't happen (like dead characters coming back to life, quests getting bugged because you do things 'in the wrong order' and so on). If there is a right order in which to do things, doing them in the wrong order shouldn't be possible at all. If there isn't a right order in which to do things, well, then that needs to be taken care of during the design phase.
The main problems on the PS3, however, are the degenerating framerate and the freezing-issues (not to mention the overall poor framerate). Those things should have been found, especially since very similar (if not the exact same) problems still exist and remain unfixed in at least two other games I know of - Fallout 3 and Fallout: New Vegas.
Postponing the game is not a viable option, release a day 0 patch is the best course of action but no developer in their right mind will release a game knowing it has huge technical issues...I suspect that Bethesda simply did not know the extent of the issue till after it appeared...now they are working on it after seeing the issue and reviewing savefiles.
Well, I think they should have known (or at least suspected) the extent of the issue, because it's there in earlier games. Yes, I know they have stated that the problems aren't the same, but I find that very hard to believe because the symptoms are the exact same (the longer you play, the larger your savefile, the more problems you will have - and the problems that you get are the exact same as in the previous titles), the games are very similar in how they function, the platform is the exact same one.
Add to that the fact that they have stated that the game runs just as good on the PS3 as on the Xbox (this was prior to release), the engine is brand new (which it isn't - it's been overhauled) and most of all their previous track record, and it's just really hard to trust such statements.