Mary-Jo Foley posted the maximum specs for Windows 7 netbooks

Screen size: With XP and Vista, maximum allowable screen size was 12.1 inches; with Windows 7, it will be 10.2 inches

Storage: Maximum limits for XP and Vista: 160 GB HDD or 32 GB SDD; with Windows 7, it will be 250 GB HDD or 64 GB SDD

Graphics: With XP and Vista, netbooks/small notebooks was “less than or equal to DX9; with Windows 7, there will be no limitation

CPUs: With XP and Vista, netbooks/small notebooks had to have “single core processors that do not exceed 1 GHz frequency, or Intel Atom (N270, N280, 230, Z500, Z510, Z515, Z520, Z530, Z540, Z550); Intel Celeron 220; AMD (MV-40, 1050P, TF-20, Geode LX, Athlon 2650e, Sempron 210U); VIA (C7-M ULV, Nano U1700, U2250, U2300, U2400 or U2500). With Windows 7, the maximum will be “single core processors that do not exceed 2 GHz frequency, and have a CPU thermal design power that is less than or equal to 15 W, not including the graphics and chipset.

Report: Microsoft readies new maximum specs for Windows 7 netbooks