There may have been some confusion when Microsoft announced Windows Phone 8′s support for external MicroSD memory cards and what exactly you could do with those. In Microsoft’s slide you see the Micro SD Support headline along with “Photos, Music, Videos, Installing Apps.” Some may have interpreted that as the ability to install apps to a MicroSD card and then transfer that card to a new phone in order to run those apps from a new phone. That’s sort of how it worked back in the old days of Windows Mobile.
That is not what this feature is about though. You still have to install apps to the main memory of the phone, however you can copy installation files to the MicroSD card and use those to install apps to your phone. It’s mainly a feature designed for enterprises who want to bypass the Windows Phone Marketplace in order to sideload custom apps to company phones. I imagine if you aquired a XAP installation file from a developer or made a few yourself, it would be good to keep them on your MicroSD card so that you could reinstall those custom unpublished apps whenever you feel like it.
Hence it’s important to keep in mind when buying a new Windows Phone 8 that the internal memory size is still going to be important for the number of apps you choose to install. You’ll really only be able to offload music, movies, and photos to your MicroSD storage card. Personally I’m okay with that since Apps installed to a storage card always seem to have issues anyway and most of my high-file-size content is probably music, photos, and videos… though it would be nice to keep offline map data on a storage card as well.
Is the inability to install apps to an external storage card going to be a big deal for you come Windows Phone 8?
Source: CNET Asia