Third party applications geared towards podcasting are all over the place these days and that's a great sign that developers and venture capitalists consider podcasting worth spending money on.
The next logical step is for a third-party and open source application to hit the market.
I'm not sure how data plans work in many places of the world, but I know that in Canada you'd have a hard time affording a data plan that would allow you to effectively use a mobile device as a podcatcher. We only have 3 national cellular providers here (Bell, Telus, and Rogers) and they all charge an arm and a leg for data. A typical data plan here is about $30-$40 for 8-10MB per month. With many single podcasts eclisping that number, mobilecatching isn't really viable here yet.
Excellent idea, however, and as long as cellular customers let their providers know that they want to mobilecatch, the data plans may come in line.