Merom is "a mobility-optimized, dual-core processor based on the new, state of the art, Intel Core microarchitecture" according to the company.
Intel's next generation notebook chip is due to be announced today alongside Conroe, the corresponding desktop chip. Merom will be marketed as the Intel Core 2 Duo Mobile and is destined to replace the current 2MB Yonah chips found in MacBook Pros.
Merom comes with a 667 MHz frontside bus and 4 MB of L2 cache, double the 2 MB found in current MacBook Pros. Intel is offering Merom in 2.0, 2.16 and 2.33GHz clock speeds, a perfect fit to drop into the MacBook Pro lineup.
A source I spoke with mentioned that Apple already has Merom chips in hand and has been testing them for a while. They're probably waiting for inventory of existing MacBook Pros to sell down and/or for the official announcement to come from Intel.
Apple will most likely announce new Intel-based Mac Pro desktops at WWDC on 07 August. There is even a possibility that Apple will announce refreshed Xserves based on Intel's new server chip (code named Woodcrest) at WWDC, but that is unconfirmed. Apple will probably roll out the new Merom MacBook Pros some time in late August.