This signing would cover both outcomes, if we are to challenge for the league title we need 2 quality strikers that can play together and also on their own. RVP can't play every game, I have a feeling this is why his form over the last 2 months of the season dropped. If podolski plays out left, then RVP and guild will rotate, one will play CL and the other will play the league, and vice verca. Also it would put RVP under a bit more pressure, at present RVP could play terrible and still would not be dropped, if he was having a poor run of form, he would know that there would be someone ready to jump into his place, that's something that we haven't had for a while.
On the other hand if RVP is going to leave, at least wenger has learnt from last year and got someone in early, so all round this would be a great signing no matter what happens.