I have the same situation as you, except I drafted Biggio intending to use him as my 2B, and drafted Walker to fill in until Biggio becomes eligible.
If the beginning of the season is any indication, Walker will not play everyday, being benched in favor of Hairston on occasion. Biggio may not be attractive as an OF, but those that were smart enough to draft him as a 2B will be getting a top 6-7 player at the position (at least).
I was laughed at during my draft for taking Biggio in the 20--something round; I believe I received quite a bargain!
C M. Montero
OF J Upton, McCutcheon, Choo
Util Kendrys Morales
SP Gallardo, Bumgarner, Latos, Zimmermann, Luebke, Jaime Garcia, Hughes, Burnett
RP League, Marshall, Betancourt