The Brewers will receive the final pick in the first pool, which drafts between the first and second round. This year the sixth pick in the pool was #39 overall, where the Tigers selected Texas pitcher Corey Knebel.
Here's a quick explanation of how Competitive Balance picks are distributed, via the MLBTR link above:
"The teams in the 10 smallest markets and teams with the 10 lowest revenues were eligible to be entered into the Round A lottery. This doesn't mean there were 20 teams in the lottery, as there's overlap in that criteria. All teams who don't win a pick in the first round are re-entered into the second round, along with any team that received revenue sharing this year."
It's also worth noting that these picks can be traded, which is not true of any other selections in the MLB draft.
As things stand right now the Brewers project to draft pretty early in the 2014 draft, so with this pick added it's possible they could have three picks in the top 45 or so next season. That's a far cry from 2013, when their first pick was #54 overall.