I think the difference between this and what we watched as children is nostalgia...many of us will look at this version of Thundercats and say 'that's not right' simply because it's not what we watched as children. This version seems to have the heart of the original and, IMO, similar art style (animation however seems 'off' for me) so it could be interesting. Bottom line though, if they threw our Thundercats on line now, we'd all go "Oh my god." Can anyone honestly say they watch the show now and get the same exact enjoyment out of it? NO, that would be impossible, we are different and the show was important to us because of how it was 'then.'
If nothing else, this version allows us to introduce our children to our childhood on their level and still let them enjoy it by 'today's' standards. Our childhood is not 'destroyed' by this, certain elements are simply reimagined for today's world. Running home every day at 3 in the afternoon to watch 'Voltron' will always be part of who I am. and yes, the trans-dimensional Voltron did happen, it just wasn't 'my' Voltron and therefore, not important to me...
Same can be said for Star Wars, just with a lot weaker story lines than the original. I truly believe JarJar was brought in to hold the 'child appeal' and then was the one behind creating Emperor Palpatine so all the parents would be justified in their hatred for him.
Indiana Jones makes more sense once you realize the storylines are plucked from the pop culture in which the movie is based chronologically:the 1930s were rampant with jungles, explorers, mystic treasures, etc. (here we have most of the 'original' Indies). the 1940's were all about aliens, nuclear fallout, the russian/nazi scare, and here we have the Crystal skull (PS the russian actually sunk a lot of time and resources into a 'mystical arts' program to find the perfect telekinetic/telepathic (whatever) soldier, so this also fits historically) and "aliens built it" has been a staple of pop culture for a long time....
Transformers: well, that one can be described by answer the question 'What if they were real.' Also the fact that Michael Bay directed them should've given us a hint. I'll always wonder what would've happened if it was directed by JJ Abrams, but do not fault him for the way he redid Star Trek and still kept it it's own thing for it's own reasons. He restored my faith that reboots can happen and still be as good as (if not better than) the original. Compare 'Star Trek: The Movie' to JJ's "Star Trek" and tell me JJ's wasn't better, even in context of their original time periods.
Oh, and for those who are interested:
Original THunderCats can be found here!
http://www.hulu.com/search?query=ThunderCats&st=0&fs=