Arrandale is a dual-core Westmere 32nm CPU with 45nm IGP graphics on the same socket. Intel calls this Multi-chip platform and this is the beginning of all integration path that both Intel and AMD plan to follow for netbooks and notebooks.
You can bet that next generation notebook chip should end up with an IGP fusioned with CPU and this is exactly what AMD plans with its Fusion chip, whenever it gets it ready. Both such chips are likely coming in 2010 some earlier some later. Arrandale will go after Core 2 Duo, the whole generation, and it should be able to outperform it.
Arrandale is a dual-core 32nm cpu supports hyper threading and total of four multithreaded cores and Intel hopes that this will do well in notebooks. At launch in Q1 2010, at least some of the partners should be ready to disclose their Arrandale powered netbooks. We cannot confirm it at this point but most likely Intel will brand Arrandale Corei3 but there is a chance that some higher end SKUs will end up with the Core i5 brand.