I'm not really sure how we should refer to the market segment just above netbooks, but below things like the MacBook Air, since I always though those were called... Notebooks. Anyway, Intel launched its SU2700 Pentium processor, accompanied by a new chipset, for this market. It runs at 1.3Ghz (dual-core), has an FSB of 800Mhz, and consumes about 10W, which is about a third of regular notebook chips.
AMD is countering this new chip from Intel with its dual-core Athlon Neo line of processors. The dual-core version has twice as much L2 cache (1MB vs. 512KB) as the single-core variant (launched in January 2009), and also comes with an integrated DDR2 memory controller. Clock frequency is unknown, but El Reg speculates it could be above 1.6Ghz.
AMD had lots more to offer, which packs six cores and is aimed at the server market. The company also released the Athlon II X2, which runs at 3.0Ghz, and a 3.1Ghz Phenom II X2.