Launched in September this year the E-400 is a 10 megapixel DSLR that is competing directly 
with the Nikon D80, Sony Alpha A100, Pentax K10 and the Canon EOS 400D, so it’s certainly got its work cut out for it. It has a list price of £849.99 in a kit with two zoom lenses of 14-42mm and 40-150mm (equivalent to 28-84mm and 80-300mm respectively) and although it is available for around £800 online, it is apparently not currently available body-only, which makes it significantly more expensive to buy than any of those models except the Nikon.
The first thing that strikes you about the E-400 is its diminutive size and light weight. It is, at the time of writing, the smallest and lightest digital SLR on the market, measuring 129.5 mm x 91 mm x 53 mm and weighing only 375g body-only. Compare this with 126 x 94 x 65mm and 510g for the Canon 400D or 132 x 103 x 77mm and 585g for the Nikon D80. It is the first E-series SLR that I feel really uses the size advantage of the Four Thirds system.
It looks even smaller because it lacks the large handgrip found on most other SLR cameras. Its slim body shape is more reminiscent of an early 1980’s-vintage film SLR such as the Nikon FG or Canon A-1. It does have a handgrip of sorts; the body shape is slightly sculpted on the right hand side both front and back with a textured rubber panel on the front and on the thumbgrip, but anyone who is used to the shape of most modern SLRs will find that the E-400 feels very skinny and possibly a little awkward. Personally I quite liked the feel of it, although I did find that the position of the right-hand strap lug was too low and pressed into the side of my middle finger. TrustedReviews - Olympus E-400