Both Nick Fairley and Mikel LeShoure (1st and 2nd round picks, respectively) were good values- they were picked later in the draft then their consensus top 100 ranking. Titus Young, however, was a 13 spot reach. Overall, the Lions nabbed good value with their picks. Fairley is clear evidence for a Best-Player-Available approach (covered extensively by Net Rat) as tackle is not a position of need for the Lions.
The ranking neglects both need and trades, two key factors in the draft. How badly were these players needed by the Lions? This is certainly a hot topic amongst fans; Mike Schottey covers this extensively. What about trades? The Mikel LeShoure pick looks good above, however it doesn't take into account that the Lions had to trade back into the second round to get him. Essentially, the Lions used two picks to get LeShoure, making the value calculation difficult. Need is subjective, so I do not attempt to include it in my analysis. Trades, however, likely can be accounted for, but I am not sure how to approach this yet.
Because the consensus rankings of players are essentially the sum of many opinions, I offer this interpretation of the Lions' draft: there is no clear, desperate reach where the pick value is strongly negative. This continues to provide evidence that Mayhew's approach is one that values talent over need. It also provides context for the Titus Young pick: as high-value line backers flew off the board early in the second round, the Lions could have easily reached for a lower-valued 'backer at 44. Rather, they let a higher-ranked WR fall into their laps. Following these patterns, neither the Fairley or the Young pick surprised me in the slightest. Trading back into the 2nd, however...