Collectibles blog, "Cult-Stuff" posted about the printing company Cartamundi, which prints Magic the Gathering as well as a host of other CCGs, having notified manufacturers that they would be increasing their prices at the end of this month in response to the increased cost of pulp. The Cult-Stuff post links to a BusinessWeek.com article that explains the increased price is due to the Chilean Quake as well as a Finnish strike.
Update 3/15/2010: Our Wizards PR contact, Jessica Sheets, when questioned if this meant an increase in booster and box prices answered that there was no comment at this time. So it is unclear whether or not this will lead to an increase in Magic packs and boxes at this time. It is unlikely that they will directly increase costs to the customer and will instead leave the MSRPs while decreasing the discounts for distributors, thus causing retailers to pay increased prices.