The title of the post pretty much sums up what we needed to tell you. We've heard previously that the Q5 is likely to go on sale at the very start of July and Carphone Warehouse in the UK are also confirming that.
It looks like at the moment they only have the black variant up for grabs. Prices start from £21 per month but for that you only get 100MB of data. On a 3G plan you're really going to need to be on a £26+ monthly plan realistically.
The other option of course is to get the BlackBerry Q5 on the EE network as currently they are the only UK carrier that have 4G in place. Those prices start at £36 per month which is a little steep but at least with CPW you have a huge selection of carriers to choose from as well as price options.