As I'm not fussed to log the minute servers are open I did a quick search around and instead of paying £44.99 for digital copy I ordered classic boxed copy with a promise of arrival on the date of the launch for £27.91.
If you're living in UK and you don't care about "being there first" ... to see the chaos and frustration that is typical on Blizzard product launches order your copy through Tesco Entertainment. Use GAMES5 discount code on check out and you saved £17.08 ... that in my case will be spend on golden support liquid that will be flowing through me during my gameplay
And yes if you ask, I used them before and sometimes I got the games day before the release date. Never happened to be late.
Edit... Lol just realized how my post sounds like. I have to ask Tesco to put me on the payroll hehe.