No, it's pretty much fact.
Favre (20 seasons):
Never a serious injury...NEVER! That's unheard of and simply cannot happen without some form of luck.
6,902 completions, 10,022 attempts, 62% completions, 70,779 yds, 7.1 yd avg, 504 TDs, 328 INTs, 110 fumbles, 86.3 QBR.
Manning (13 seasons):
4,429 completions, 6,830 attempts, 64.8% completions, 52,312 yds, 7.7 yd avg, 381 TDs, 183 INTs, 37 fumbles, 95.5 QBR.
In the next 7 seasons (if Manning can play that long), he'll need the following numbers to "catch" Favre;
2,473 completions (roughly 353 per season), 3,192 attempts (456 per season), 18,467 yds (roughly 2,638 per season) and 123 TDs (roughly 17.5 per season).
My money says Manning will exceed Favre in every meaningful statistic...