Whilst iOS8 may have been announced like 6 months ago, it's largely an initially unstable and certainly not fully featured release until the latter parts of the beta if that. Functionality that may give future iPhone specifications away such as screen resolutions are closely guarded even within development beta.
Add to this an often mandatory upgrade (but not necessarily backward compatible) of development environment when using beta versions will put many developers off from testing their app on beta until beta 6 (Early/Mid Aug) or Gold Master (Early September).
I'm sure that many would be pleased that people like
Enno are spending their time casting their mind forward to new things rather than getting distracted with 6 months testing with moving goal posts of what may well be a 'legacy' app.
A different story if Meridian were a big software house, but they are not. IMHO.