There are a few companies producing small, inexpensive iBeacon emitters but it seems to me that Estimote are the most popular right now. Alasdair Allan and Sandeep Mistry have investigated and discovered that it's fairly easy to modify the settings of a beacon remotely which is going to be a concern if you are implementing them. One thing definitely worth noting is that it is very clear on the documentation that current hardware and software is a developer kit and not final so maybe this will be modified with the final release.
I hadn't come across this bug myself but it's a big one and I have seen many people on Twitter bashing their heads with this over the last few months. Peter Steinberger (with help from many others) has published PSPDFTextView which implements a work around for the problem. Looks like this is going to be an issue in iOS 7.1 as well but fingers crossed for 7.2. If you haven't come across this issue the animations on the readme file explain the bug very effectively.
Like Ash Furrow, I read Dave Schukin's post earlier this week on how we should write code with the plan that it will need to be rewritten with a future iOS update. It's true that in the early days of iOS that large portions of apps would need to be rewritten regularly, the frameworks were much less refined and developers were still learning how to use them. Clearly, as iOS is moving much faster than OS X and the web, more code is going to need to change between versions but I'm not sure that we should build for obsolescence now we have got to version 7 of the OS.
Keith Harrison with a great rundown of the text to speech APIs in iOS 7. I hadn't really thought about it before but naturally this is multi-lingual as well, what a fantastic resource to have available to us as developers.