Though I've had this information on good authority, this is probably still one for you to file under "I'll believe it when I see it". When a music festival is announced in China (and this one's not yet official) it's never really certain that it will take place until usually a couple of days before - and some times even that's no guarantee. Midi, for some reason, seems to be particularly adept at creating their own melodramas in the run up to their events and generates more gossip and rumours than all the other festivals put together. Just a few weeks ago, the word was of Midi going to Chengdu, the current talk is of it being in Wuhan and there's even whispers about a Midi in Anhui in 2010. Add to that the failed attempt to bring Midi to Shanghai back in May (when it ended up being in Zhenjiang instead) and you've got yourself a recipe for skepticism.
It'd be great to have a festival like Midi in Shanghai, but, if it does come, is Lingshi Park really the place to put it? It hardly seems big enough to be honest. JZ have got their annual jazz festival out in the huge Century Park in Pudong in mid-October - a different breed of festival of course, but a far more suitable venue you'd think.
Then again, Midi Shanghai is still a long way from being confirmed. Don't get too excited just yet.