OCZ is announcing some new SODIMMs in their lineup, designed for higher end laptops that can support DDR2-800 speeds. The new modules, available in either 2GB or 4GB kits, are some of the fastest SODIMMs available and are designed with "performance" laptops in mind. Laptops with 4GB of RAM are few and far in between, though it is increasingly common for a stock machine to be upgraded post-purchase, particularly when people realize that Vista really frowns upon having (relatively) small amounts of RAM.
The new kits are clearly aimed at the Santa Rosa platform, which can take advantage of these modules rated at 5-5-5-15 and 800MHz DDR2. The modules will be available individually in 1GB or 2GB sticks, as well as in 2GB or 4GB kits, though they are not yet available. OCZ is not releasing availability or specific pricing, but judging from the price of their other DDR2 SODIMMs you can probably expect a 4GB kit to go for well over $300.
You can read more on OCZ's product page.