In many ways it depends on your business and who you are meeting. Many companies in Dubai have western staff but if you are meeting with locals, then sleeveless is not really suitable. Everywhere is air conditioneds, so I would put a jacket over the dress. In the Middle East you want to cover shoulders and ideally skirts should come below the knee. And definitely no cleavage on show HTh
To be honest, I wouldn't wear sleeveless, have you not got a jacket that you can put over it? If you have a trouser suit I'd wear that and no low cut tops as it can be considered offensive. Also bear in mind that arab men might not want to shake your hand. Nothing insulting meant, its just the way it is with their culture.
Found various bits of vague advice online about no cleavage or short skirts but I'd appreciate some first-hand advice if possible.
I'm travelling on Sunday only found out today, have a v limited wardrobe but the only things smart enough and suitable for a warm climate are sleeveless dress of about knee-length. Is sleeveless acceptable? And what about bare legs or do I need go get some of those horrid skin-coloured tights? Or would that not help and should I stick to trousers?