Some of the modern authors heavily influenced by Lovecraft are also worth checking out. Others already noted Ligotti, but Ramsay Campbell, Richard Lupoff, and the late Karl Edward Wagner come to mind. Neil Gaiman has also written a few mythos tales.
If anyone is looking for non-Western contemporaries involved in the mythos, they would do a lot worse than to read any of the "Lairs of the Hidden Gods" volumes put out by Kurodahan Press. There are four in the set, and each one includes some of the best translated mythos works from Japan. I found editor Asamatsu Ken's stories to be fairly effective, as well as first volume offerings from the minds of Kamino Okina and Murata Motoi. You can learn about the first volume here:
http://www.kurodahan.com/e/catalog/titles/j0010.html
Though not quite an author of purely textual Lovecraftian art, Junji Ito is of interest too as another Japanese writer. He has created some very Lovecraftian manga comics and helped produced several films. His latest manga is supposedly the most Lovecraftian to date, but alas, not translated into English (yet). His wikipedia entry is here:
http://en.wikipedia.org/wiki/Junji_Ito
Hope that helps, gents.
