Alchemy is a stealth skill now? I just checked to see if it was one in the other two non-DOS games in the main series, and it isn't in those. I have no idea how this skill would make sense as a stealth skill when it seems more like a magic skill.
It's been known what "class" each skill falls into in Skyrim since some time last year. They changed Alchemy to Stealth to make an even 6 for each archetype. I do think it makes since, though, given the prevalence of Alchemy in poison making, invisibility potions, boost potions, and the fact that it is a great money-making profession, which pairs it well with Speech(another skill in the Stealth section).