Following the launch, yesterday, of the new LTE-capable iPad 3rd generation, Apple also increased the over-the-air download
limit for the App Store to 50MB. Previously, download was limited to 20MB. This change, which is already active, has a lot to do with iPad’s high resolution Retina Display and is meant to help accommodate larger app size.
You should also note that this is valid for data connections too, and for anything beyond the 50MB limit, you will still have to use Wi-Fi connections. On the other hand, 50MB should be enough for most apps, music or videos, even if we think users would have preferred an even larger increase or, why not, no limit at all for those on unlimited data plans.