The basic update story of 1.5 is it's the long awaited redstone update. But what does it add that you really need for redstone use? Not much. for starters, the only bit of the update i see myself using it the hopper and daylight sensor. But as for what it adds? In the multiplayer server I play in (currently), all it has added was unbearable lag. it was so bad as to the point it took me 5 minutes to craft 1 item frame. And if your using a texture pack, better hope it's updated. other wise Minecraft will switch right back to default textures. And if you like the skin you have (if it's not the default Steve skin), then you better remember where it is. For my skin and tons of others got reset. mine took 2 tries to get it to work again. So comment what happened to you down below! And diamond/favorite if you think this deserves it! this my actual experience with the update, so yours may have been different.