First off I want to say that I have nothing against Christian Ponder. He was by all accounts a bit of a reach at #12 and I'd say that so far he fills that bill. That isn't to say he's bad. He was projected more like #30 overall, which is still very good, and I'd say that is more how he looked in action. I don't think Ponder will ever be an elite light-em-up kind of QB but more of a solid game manager that could succeed with a strong defense and rushing attack. And with how often he needs to leave games I'm not so sure he's a viable starter to be quite honest and might be better suited for the bench.
But Luck and RGIII are two of the best looking QB prospects since Peyton Manning. They are off the charts. They are 10 or 15 slots higher than all of the other players in the draft. The only reason you would pass on them is if you have an elite QB, and elite prospect, or a QB you owe a whole lot of money to. Vikings have none of the above quite frankly. There just isn't any reason to pass on them unless they get a huge deal to trade down.
With that said, the Rams have Bradford and are committed to him. They will trade down with the Browns and ensure themselves either Kalil or Blackmon. But if by some miracle the Browns decide to take a chance on RGIII still being available at #4, the Vikings need to do the smart thing and take RGIII, trade away either Ponder or Webb, and do whatever else they can in the draft.
Watch RGIII highlights. Ponder is nothing in comparison to this guy. The problem though is that the Vikings are likely "committed" to Ponder on some idiotic pride level and will build the offseason around him and Frazier's old coaching buddies and be content to march out the same losing combination next season. ugh.
BTW I'm an RGIII fan.