Given the (sound commercial) reasons that VLM have given for pulling the MAN-LCY route why would any business, especially in the current economic climate, "take a punt" on the route.
Only in the UK, with it's pathetic high speed rail infrastructure, would such a short route be even considered viable - given that the traffic is point to point with little or no interline prospects. Flying, with all the security issues is now pain in the proverbial, and rail, without all that check-in and security hindrance should surely be the preferred option for city centre to city centre travel over comparatively short distances.
When, or more realistically, if high speed rail is developed properly in the UK then it would be the deathknell for much of the current domestic point to point air travel - as it has become in France, and Germany.