Ok, here goes.
3rd May -> 9th July: New Zealand tour England (3 Tests)
12th May -> 8th June: Bangladesh tour West Indies (2 Tests, 3 ODIs)
17th May -> 18th June: Australia tour Zimbabwe (2 Tests, 3rd ODI)
16th June -> 23rd August: West Indies tour Ireland and England (4 Tests)
24th June -> 10th July: Nat West series in England (England, New Zealand, West Indies)
24th June -> 13th July: Sri Lanka tour Australia (2 Tests)
30th June -> 30th July: Sri Lanka A tour England
16th July -> ? August: Asia Cup in Sri Lanka (Sri Lanka, India, Pakistan, Bangladesh, UAE, Hong Kong)
22nd July -> 25th July: New Zealand Women tour Ireland (3 ODIs)
28th July -> 29th August: Bangladesh Under 19s tour England (3 Tests, 3 ODIs)
30th July -> 30th August: South Africa tour Sri Lanka (2 Tests, 5 ODIs)
5th August -> 24th August: New Zealand Women tour England (1 Test, 5 ODIs, 1 Twenty20)
26th August -> 5th September: India tour England (3 ODIs)
8th September -> 25th September: ICC Champion's Trophy in England (All 10 test nations plus Kenya and the USA)
8th December -> 13th February 2005: England tour South Africa (5 Tests, 7 ODIs)
13th February 2005 -> 15th March 2005: Zimbabwe tour South Africa (2 Tests, 3 ODIs)
Still to be scheduled
August 2004
One Day triangular series in Holland in August (Australia, Pakistan, India)
October 2004
Zimbabwe tour Pakistan
New Zealand tour Bangladesh
Australia tour India
November 2004
South Africa tour India
England tour Zimbabwe
Sri Lanka tour Bangladesh
New Zealand tour Australia
December 2004
Pakistan tour Australia
Sri Lanka tour New Zealand
Hope that's enough!