I am a fan of Autograph Weekend dresses - my favourite 'brand' in M and S by a mile - and check every few days on the website what new ones have come in. If you do the same - which I realise you probably do already - you're very likely to see other dresses similar to that one, as they do tend to do variations on a theme.
I like their stripy dresses which can be worn as tunics - latest one I've acquired is this:
www.marksandspencer.com/Autograph-Weekend-Stripe-Jersey-Dress/dp/B005OTZS5O?ie=UTF8&ref=sr_1_8&nodeId=192501031&sr=1-8&qid=1319388327&pf_rd_r=0TWYEXB6H093KC6QB8TN&pf_rd_m=A2BO0OYVBKIQJM&pf_rd_t=101&pf_rd_i=192501031&pf_rd_p=215570647&pf_rd_s=related-items-3
Not original but very wearable and versatile.