I think Ludwick's 2 year deal precludes a Choo extension as an option. I also think it's wishful thinking that Choo will command less than a 5-6 year deal.
If Ludwick has a decent season in 2013, wouldn't it be fairly easy to trade Ludwick? If Ludwick drops off significantly in 2013, you just don't pick up his option next season. If he has a great 2013 you should be able to get something good back in a trade.
It may be true that it will be difficult to resign Choo, but I don't see Ludwick blocking the path for anyone.