Amazing Grace Sunday is in March for the United Kingdom. The city of Hull is leading a Wilberforce 2007 celebration and anti-slavery campaign.
This year July 30 is the memorial for Wilberforce in the Anglican liturgical calendar; usually it is the 29th (the anniversary of his death), but this year it falls on a Sunday, so the memorial is moved. The collect used for his Feast is appropriate:
Let your continual mercy, O Lord, kindle in your Church the never-failing gift of love, that, following the example of your servant William Wilberforce, we may have grace to defend the poor, and maintain the cause of those who have no helper; for the sake of him who gave his life for us, your Son our Savior Jesus Christ, who lives and reigns with you and the Holy Spirit, one God, now and for ever. Amen.
Expect plenty of events related to Wilberforce and abolition between now and then.