Toshiba and SanDisk, who are industry partners, are looking to expand their manufacturing capacity with joint construction of a new flash memory plant. Located in Japan, the plant will be producing NAND flash products and is expected to be able to produce wafers for manufacturing in large quantity. The NAND market has been growing rapidly, and Toshiba expects that to continue:

Toshiba expects the global market for NAND flash memory chips to grow from an estimated $16.19 billion in 2006 to $22.62 billion in 2008, when the Tokyo-based company and SanDisk aim to take a combined 40 percent share in that market, up from the current share of about 30 percent.
The two companies aren't going to sit on what they already have, but rather aggressively go for expansion. The new plant is part of that, and hopefully the future impact will be cheaper flash products for everyone.