Both Wizz and easyJet used to serve Krakow from BOH back in 2008 or 2009. It was then discontinued as the route had two airlines flying 6 times per week - too much capacity. This time FR will certainly prove the route to be very popular - there are huge numbers of Polish people from this part of Poland living in Southampton and Bournemouth.
Previous Polish routes from BOH:
Wizz tried Gdansk, Krakow and Katowice (Year-round)
easyJet tried Krakow (Winter season only)
Ryanair tried Katowice and Wroclaw (Year-round)
Potential new Polish routes:
Warsaw would be strong, BOH should be targeting Wizz to return for this one.