Just had word from a friend whose been filming as an extra on the set, yes indeed this is the new suit used in the third series, and it does look a bit cheap.
He says:
I can confirm the following, having stood right along Dr Tennant on set for some time (BTW, he's very... stand-offish Didn't mix with any of the crew or other cast and there were stories about extras being told off for speaking to him... but that's another story)
Anyway, the suit looks very thin and wrinkled, although not in a fashionable linen way. It is a medium blue, thin fit jacket and trousers with thin brown stripes . Top left breast pocket is buttoned 'safari style', while bottom two are normal flaps. Yes, the new shoes are red Converse and he's wearing a light blue shirt and non-descript red patterned tie.
The new girl looked very professional in her white dr's coat. Should prove interesting conversations in the TARDIS: "Dr?' "Yes, Dr"...
