its not all about the pixels...
my nikon d40 was 'only' 6Mp - that took FAR better a picture than a 12Mp compact...
it's all about the size of the sensor, the glass (lens) in front of it and the schmuck pressing the button....
£400 will gt you a nice top end compact, but it will also get you an excellent entry in to dSLR, but you dont have to spend thousands on lenses... right away....
http://www.warehouseexpress.com/buy-nikon-d3000-digital-slr-with-18-55mm-vr-lens/p1032941thats £340 for a nikon dSLR, new, the lense is plenty wide at 18mm but the zoom end at 55mm isnt much of a zoom. On a compact its maybe 3 times zoom, its hard to compare like to like. if you find you need more zoom you 'can' buy a 55-200 lens, in fact, i know someone selling one so i bet you can have the lot for £400.
its a great start, thats the equivilent of my old d40 which i sold on to Baz when i upgraded to my D300.
all im saying is, theyre worth looking at... get yourself to a jessops or something and fiddle with the cameras, you might prefer the menu system on a canon for example (freak!!)
but remeber.... NASA give astronaughts a nikon to take to the moon... canon make photocopiers and printers !!!