Salvia divinorum is still perfectly legal in the UK and most of Europe, but there are exceptions, and situations can change.
More information on laws regarding Salvia divinorum can be found at The Salvia divinorum Research and Information Center at Erowid's Salvia Law vault, and at Wikipedia's article on the Legal status of Salvia divinorum.
Generally Salvia divinorum is legal in most countries in the world and, within the United States, legal in the majority of States. However, a few politicians have called for its prohibition. At the time of writing, most of these proposals have not made it into law, with motions having failed, stalled or otherwise died, for example in the United Kingdom, at national level in the United States, and at more local level there within States such as Alaska, Illinois, Oregon and Wyoming.
A reason for Salvia's favourable legal status so far is that there's been no evidence to suggest that its use is problematic.
Despite this, some have succeeded in pushing though their anti-Salvia laws, such as in Australia (the first country to ban it), and in a few American States. Some of the contentions used by some politicians to justify prohibition are dealt with in the next section.