Hugin currently outputs complete verbose progress messages in big windows (redirecting the helper applications' output), BTBatcherGUI lets the user check "Verbose output" or let it be.
I would prefer very much to have a non-verbose status display, possibly the well known bar type. An average user is not very interested whether it's a Gaussian or a Laplacian pyramid that is currently worked on - but rather wants to know which image number out of how many is currently being processed. In the status windows you can find the numbers (you must know that you have to add 1, though), but you have to remember the total number of images. So a simple window "processing image n of m" would be good (counting from 1).
If the progress bar is too difficult to implement because the speed of the different processing steps can not be estimated in advance, then a window with one bar (or an image count "n of m") per step of the chain would be good as well.
I'm afraid this would involve changes in all helper applications or implementing an interpretation of their output. But it would make hugin more appealing to less technically oriented users who might be frightened by so much output they don't understand.
2015.0 contains now a simple progress indicator.