I do have doubts that these samples were from T4 victims, given what I have read about the program. This institution catered to adults (as far as I know), and unlike children, they seemed to have been cremated en-masse rather than carefully dissected and examined.
Also, as Seventh has pointed out, these bottles don't seem to be very well secured and much of the formaldehyde was probably lost due to this fact - so the chance that these tissue samples date back to the 1940s is highly unlikely.
But those are just my assumptions based on what I've seen, that's all.
I'm not freaked out by the samples themselves, or by legitimate medical useage in hospitals. I don't even mind the surgery channel, etc... Biology is fascinating. What bothers people, I think, is the fact that the whole T4 thing (which was bad enough), led to many of these "samples", coupled with the fact that what was left of those poor peoples' bodies were left to rot in an abandoned building.
Again, OK when "handled appropriately", (cleanly stored in a storage room, etc...), but CLEAN THEM OUT when the building is closed (or get it taken care of soon after).
Hmmmm.... I just think these should be at least disposed of in an appropriate way, not just left to literally rot (not to mention a biohazard). No, I'm sure the people themselves don't mind anymore ( :-l ), but it just does not seem RIGHT to have these just LEFT there instead of being cleared out and taken care of. I understand genuine medical samples for unusual conditions, for purposes of study, but handled appropriately. It just seems disrespectful to just abandon things like that, especially with the circumstances that led to the deaths (which were horrible anyway).