Lego's first set of dinosaurs released in 2001 mutated dramatically when the new series emerged last year. Looks like they spent the decade pumping weights, downing protein drinks and tanning. A brief comparison of the old and new T-Rex is posted here (pardon the photo quality, I take these in haste at the end of a long evening. Once the layout is done I chronicle the results with more care).
I'll probably still use some of the old ones - a few of which were more fantasy than archeologically accurate - just for the heck of it and to populate the layout without spending more money on the newbies.
Another thing that has changed substantially in the Lego universe: Toilets. After decades of apparently avoiding the basic bodily functions, Lego has embraced them. The first Lego loo I came across was included in the modular building series Pet shop (photo included for reference) used in last year's Harry Potter layout. Friends kits include not one but two sets with a privy: one in Olivia's house, and one in the Summer Riding camp. the latter even has a roll of paper, and a label on the outside door: W.C. (both kits have shower stalls as well).
And just to make it clear I don't have a latrine fixation, a picture of Aurora contemplating a passing monorail. She has yet to take a swipe at it.