Update 1.02 is now live for the GTA Trilogy - Definitive Edition and it includes 61 fixes, including changes to the much-maligned character models and weather effects.
Yesterday, Rockstar finally responded to the criticism that the GTA Trilogy was receiving, admitting that it wasn't up to its own standards and that fixes would be coming very soon, saying that "the updated versions of these classic games did not launch in a state that meets our own standards of quality". As it turns out, "soon" meant a day later, as the first update for the game is now live and fixes a range of different issues that players were reporting.
The list of changes made in the update can be found on a post over on the Rockstar Support page. There are a lot of changes made to each game, but all three have received fixes for incorrect textures, holes in the map, missing collision, audio files not being played, and localisation issues.
GTA 3 has received the least changes out of the trilogy, with most of the changes being made towards character models not animating during certain cutscenes, and a few glitches, such as, "an issue where the player can boost their running speed by quickly swapping through weapons". A fix for the glitch that has cars growing in size after moving side-to-side doesn't appear to be in the game yet.
Meanwhile, GTA Vice City has received a fair amount of fixes, with some of the most notable ones including fixing a lack of camera control when in cars, fixing a t-posing Tommy Vercetti during certain cutscenes, and a few instances of no GPS.
GTA San Andreas has by far received the most changes and seems to have launched in the worst state. Some of the changes include fixing the infamous rain effects, adding the correct help information when swimming, adding the right animations for specific cutscenes, and mending some mission-specific bugs that were causing the camera to spin around quickly.