In case you have not noticed, a few netbook manufacturers have already started transitioning from ATOM N450 to N455 with their netbooks. ATOM N455 is almost identical to N450 but it supports DDR3 memory. The difference in speed is not going to be that much though.

While many of these new N455 netbooks are available for pre-order, these 3 models are already shipping:

Toshiba Mini NB305-N440BL 10.1-Inch Netbook: combines ATOM N450 processor, 1 GB DDR3 RAM, and GMA 3150 graphics to offer you better performance on the road. 8.3 hours of battery life is not too shabby.

Lenovo Ideapad 0647-2BU 10.1-Inch Netbook: it is ultra slim and compact. This Ideapad has 98% full size keyboard with rounded keys. Protects your hard drive against shocks too.

Acer Aspire AO533-13531 10.1-Inch Netbook: features N455, Windows 7 Starter, and a 10.1-Inch WSVGA LED-backlit display. 8 hours of battery per charge is not that bad either.

If you are shopping around for a new netbook, the above new models should give you some ideas.