Never, ever, ever buying anything from this company again. I bought my iPad 3 on the under standing it wouldn't be replaced within a year. If I had known they were going to release a faster model and making the port obsolescent within 6 months I would never have bought it, given that I'm using it for synths.
What synths? How does the new device make your one no longer usable? It's a bit shitty when this kind of thing happens, but Apple does fast updates less than most other companies. You could always try flipping your device on eBay and taking a hit—I'm certainly going to be interested to see how iPad 3s hold their value (or not).
Between that and not being able to download from the App Store more than half the time
What's going wrong? The App Store is sometimes an arse, but I've not had any long-running problems with it for a long time now.
All of the synths... and in my experience synth makers have been VERY quick to drop the iPad 1. Obviously with the current versions of apps, my current iPad is very useable, but I'd have waited if I knew the iPad 3 only had six months. I'd upgrade via eBay but I don't have disposable income anymore. I am pretty much going to stop using this for anything but music as soon as I can afford a google tablet, mind you. I have have little but bad progress from apple since buying this otherwise very capable device. Apple have fucked their chance to make a good impression on me.
As for the App Store, since iOS 6 I get cannot connect errors, with no explanation, nine attempts to get something out of ten. Really. I can often check back later and it works, but this is a near-constant problem. It was fine before iOS 6 and so I repeat: iOS 6 is shit.