As of 2009, ARM processors account for approximately 90% of all embedded 32-bit RISC (reduced instruction set computer) processors. The simplicity of ARM processors make them ideal for low power applications which is why they're used in so many mobile devices.
The entire Apple line uses ARM chips, including the iPad and iPhone line. Many Samsung and Motorola devices use them as well.
Recent price action has seen ARMH fall from over $30 just in late February, so a return to $29 by April op-ex seems quite plausible.
"Without ARM, it would take a device the size of a computer to accomplish what the smartphones in our pockets are capable of," says analyst Francis Sideco of researcher IHS iSuppli.
Wikipedia has an interesting history of the company, explaining how the Acorn RISC Machine project started in October 1983. This company has a long history, but is only just starting to get the sort of attention paid by the WSJ article I just linked to.
Obviously when it comes to chips, mobile is where it's at. And almost everyone is using ARM chips. Confidence 8.