dubious_1's comments

There should never be an expectation that your data is secure on Dropbox unless you use local encryption/decryption. Your data is sent to the dropbox server where it is encrypted by their server (according to their web site) and stored. They secure the data in transit, and then again for storage, but they have access to the keys. There seems to be strong evidence that some checking is done before file transfer to see if the file you are syncing is already available somewhere on the server, and if so the file is not transferred, but does appear sync'd in your account. I noticed this personally when I placed the Access2007 Runtime installer into a folder and the 52MB file was nearly instantaneously flagged as synced. Insecure authentication of an insecure system is not really a big deal. The lack of convenience for users if stronger authentication was used is probably a bigger concern. If I have access to your local machine such that I can extract your local credential, I would easily copy all of the existing data from that machine, and could install a key logger to catch your password.

Previous major upgrades to XCode released with new versions of OSX and required that newer version to install/run. OSX 10.7 (Lion) has not released yet, so upgrading from 3.6 to 4.0 (Major upgrade) is not considered a maintenance release by Apple's accounting department. Paying members of the Apple Developer network subscribe ($99 per year) and one of the benefits is access to Beta releases of OS and tools. XCode 4.0 was available to members of the Developer network prior to this official release, and after the release, non-subscribers are given access through the App Store. Apple is in no way preventing anyone from developing for Mac at this point since XCode 3.6.5 is still available for download and installation by any users of OSX 10.6 (Snow Leopard), and as evidenced by the availability of the iOS 4.3 SDK for XCode 3.6, they are not forcing anyone to upgrade to the new IDE just to develop for their various platforms.

You do not need to update to XCode 4.0 to develop for either OSX or iOS (even 4.3 SDK is available for XCode 3.2.6). There may be some great new wistles and bells in XCode 4.0, but it is not essential. For a hobbyist learning OSX or IOS development, it is probably better to wait anyway since all of the existing tutorials, Courses and books are still focused on XCode 3, and changing the IDE this much will probably just confuse.

You are the first to actually hit that point, and I believe rightly so. I don't see how you could actually comply with V3 and release your software on any of these stores. The obtaining of a developer signing key is not free, and there is no guarantee that the derived work would actually be accepted.