I will wear my tin foil hat here. I think this is all planned to go like Air India sale way. If the government didn't supported Vi, they would've shut shop long back as the debt is simply too much and a lot of PSB will take a hit on their balance sheet not to mention the competition elimination in India.
I think they will raise it more and more and eventually sell the company keeping the liabilities like AGR and all so the debt is siginificantly reduced for the next owner. This way, they will escape the controversy that people bring "government is waiving 1000s of crores of debt" and etc etc. This is what they did with Air India to make it attractive to sell to Tata.
I also don't think they can merge it into BSNL. Heck, they couldn't even merge MTNL to BSNL considering the operational reasons of both companies (MTNL is stock market listed and in severe debt). BSNL with it's unions and all, forget that government will even think of doing the merging and all.