According to Dejan Kovacevic of the Pittsburgh Post-Gazette via team president Frank Coonelly, the Pirates will slightly increase their payroll beyond $54MM next year.
Coonelly says the Bucs will not get involved with high-end free agents, but the money will be there if they see good baseball investments in the mid or lower tiers (free agent list here).
I did an Offseason Outlook for the Pirates on Friday. Even with arbitration raises to eight players, the Pirates should still come in around $40MM (less if Jack Wilson and/or Adam LaRoche are traded). That could mean $10-15MM to spend on free agents. I could see them signing a veteran shortstop as well as a starting pitcher.