Is iPad vlogging viable?

The camera found on the iPad and most other tablets just aren't really made to produce good quality video. They'll give you decent and somewhat usable video, but if you have an iPhone or Android Phone laying around somewhere, chances are, they'll have better cameras.

If that doesn't particularly matter to you then I hear iMovie works really well on iOS.

Vlogging using an iPad should be fine. In most cases, you want to make sure the audio is of better quality than the video. It's not that video quality isn't important, but most people will overlook some minor artifacts in video quality, but if the audio quality is bad, they won't watch the video.

This is probably due to advances in audio quality surpassing advances in video quality at this point in time. Unfortunately, audio on mobile devices is usually enjoyed using substandard speakers, while manufacturs are focusing a great deal of effort on releasing devices that have higher-resolution displays (which in some cases, such as Retina, are far better than the video that is typically being displayed on the devices. Some say this trend is changing now with advances in portable speakers hitting the market soon; Chris Pirillo recently interviewed someone at CES 2013 who is strongly of this opinion, having seen such devices.