I have an iPad, I'm currently using PlugPlayer as a DLNA Controller and MC as a DLNA Server. My DLNA Renderer is a WD TV Live box.
You could use MC as a DLNA Renderer via this route, rather than a custom iPad app to directly remotely control MC. Turn on DLNA Server and DLNA Renderer but use an external DLNA Controller to control it.
However, PlugPlayer is not "pretty" as yet and while it is slick, it only works in text mode and doesn't yet understand about browsing by thumbnails. However, I'm trying to suggest enhancements. ;-)
It would be an absolute killer app - would it be the first UPnP/DLNA controller to be able to browse a DLNA Content Directory seamlessly as though it was a native media library?? It should be able to switch to a thumbnail mode whenever the server tells it to, i.e. supplies artwork for the container and the items. And it should be able to recognise the difference between audio, photos and video.
But it requires authors of the respective programs to recognise the potential, and perhaps talk to each other??
MC DLNA server should be configurable so that you can define what images to send at what levels and whether to send images at all for that level (there is already a thread for this sort of thing -
http://yabb.jriver.com/interact/index.php?topic=60269.0).
PlugPlayer (or in fact any DLNA Controller) should be able to act on the content directory that is being sent to it and render it appropriately.
Going the DLNA route means that authors can concentrate on their own programs and not have to develop custom control apps for other platforms and devices, of which there might only be a handful of users. Just ensure that their own product complies with the protocols fully and is sufficiently configurable.