There are a few things I gather from this. The first is that the game is probably overtracked - I believe this is the case. And the second is that it has high preorders at the moment because it was announced much earlier than Uncharted 3. So it seems somewhat understandable that its preorders are matching Uncharted 3. At this point, Uncharted 3 had been available for pre-order for a fairly shorter time.
This is illustrated by the way the two curves differ from each other. The UC3 curve appears to be concave up while the TLoU curves appears to be concave down. If this trend continues then in a few weeks the lines will cross and UC3 will overtake TLoU. Also, I think a higher proportion of TLoU buyers will be more informed gamers, so a higher proportion of sales will be pre-orders without necessarily having high legs; similar to games like hardcore RPGs which can have high pre-orders and low legs.
Those are good pre-orders though and I do expect the game will be a success (around 3m, give or take 500k), but I doubt it will be comparable to Uncharted for several reasons.







