Beyond is generally used as a preposition, and so is followed by a noun: it's located beyond the river; beyond the pale; beyond belief; beyond repair, and so on. Occasionally it's used as a noun (the back of beyond) or adverb (beyond, there's a wood). There was a piece on Radio 4's Today programme this morning (listen here for another week) about how beyond is currently a fashionable word, and is used as a synonym of very or really (which are adverbs) before an adjective. So, it's becoming fairly common to hear someone say 'I'm beyond happy'. Camilla Long, a journalist and one of the interviewees in the snippet, said she used beyond on its own - 'It's totally beyond', meaning that she's so excited about something that she doesn't have words to describe her feelings. Her sparring partner on the programme, linguistic conservative Simon Heffer, felt that beyond was overused these days, was boring, and had become a cliché. Both Long and Heffer agreed that beyond in this sense was more appropriate in speech than in writing.
Listen to the clip, which is available for a few more days, here.