Some of the internal specs from the £700 A550 have been brought down into the A450. Most notably, the 14.2-megapixel CMOS sensor, and the 7 frames per second continuous shooting mode. But it comes at the cost of the A550's Quick AF Live View system (it has a Manual Focus Check Live View system instead) and its useful tilting LCD display.
What you're left with, then, is a camera that should still take terrific pictures -- over 1,000 on a single charge, just like the A550 -- but you'll have to crane your neck using the smaller 69mm (2.7-inch) LCD display to get some of them.
Other features include ISO sensitivity of 200-12,800, SteadyShot image stabilisation, and an Auto HDR (High Dynamic Range) function that caputures and combines two photos, shot at different exposure levels at the same time, to produce a rich HDR image. There's also a built-in flash, a mini-HDMI output and compatibility with Sony's Memory Sticks and more widely-used SDHC memory cards.
The A450 should be on sale in the UK in February, but Sony was unable to confirm its retail price. It should be slightly less expensive than the A550, however, which currently sells for £700 complete with a lens.