I just read about this, and I'm really confused why Microsoft is doing this.
I'm just spitballing here, but I can think of one overall mobile strategy that RDP for iOS and Android *might* serve:
To diminish the value of native apps that run on the competitions' platforms in order to reduce the perceived "app gap" between Google Play/Apple App Store and Windows/Windows Phone Stores.
This "app gap" is frequently cited as what is holding back the adoption of the latest versions of Windows as well as Windows Phone. By allowing the (virtualized) use of PC applications from the competitions' devices, the value of the wide-availability of mobile apps on the competitors' platforms can theoretically be diminished, if there exist a more-powerful PC-equivalent application that can be used through RDP on those devices.
However, by releasing RDP for iOS and Android, I think Microsoft is making a huge tactical error. The reason is that people that they hope to convince that running a Windows application through RDP is better than an analogous mobile app have already given their money to somebody else. It does nothing to convince new buyers of tablets to go with a Windows RT device, and it essentially obviates one of the few unique selling points that a Windows RT device currently enjoys.
One possible benefit to Microsoft is that iOS and Android users who happened to have a Windows PC sitting at home will be able to use their PC a little more frequently. If people decide not to dump their PC hardware, Microsoft might be able to sell an upgrade to Windows 8/8.1 on those PCs since Windows 8/8.1 are optimized for touch, which would be the primary means by which you'd be able to control a PC from an iOS or Android device. However, what are people actually going to run in this manner in the first place? A desktop application or a Windows Store app? IOW, the type of application that is best-suited to run through RDP from a mouseless iOS or Android tablet is a Windows Store app! *facepalm*
Access to Windows Store apps obviously isn't going to be a big driver for upgrades to Windows 8/8.1. If anything allowing all of those iOS and Android tablet users to access an existing Windows 7 PC at home, clunky though it may be using touch, just gives those people a reason NOT to buy a new Windows 8/8.1 Ultrabook, hybrid, or tablet. In conclusion, I have no idea WTF Microsoft was thinking when they decided to develop these iOS and Android versions of RDP client.
IMHO, the better strategy would have been to preserve the usefulness of the COMPETITION'S desktop hardware that people already own and in the process sell more of your mobile hardware as the gateway to that hardware. In order to carry out this strategy, Microsoft should have developed an RDP SERVER application for OSX and then allow remote access from Windows RT and Windows 8 tablets. IOW, you give existing Mac owners no reason to buy a new Mac should Apple ever decide to start offering touch-based Macs, but give them reason to buy a Windows tablet.
Think about it. With RDP Server software for OSX, you can buy a Surface 2, and turn your existing Mac desktop into a touch-enabled MacBook as well as a tablet that runs Windows. This is the kind of guerilla tactic Google is using on Microsoft. Microsoft refrained from releasing IE9 and IE10 for XP in order to hasten the migration to Windows 7, but Google gave XP owners reason NOT to upgrade to Windows 7 by making Chrome compatible with XP.
Granted, even the total number of people who own Macs is probably even smaller than the number of people who own iPads and Android tablets who also happen to own a Windows PC. However, this strategy at least gives *some* people incentive to purchase a new Windows RT device rather than to simply preserve the usefulness of an existing Windows PC.