Quite a lot, the pressure for Home Rule was diverted for about a decade and a half by the split between the Parnellites and anti-Parnellites. Sectarian tensions not as high without an instance of blatant direct political interference by the Catholic church. Thomas Nulty (Bishop of Meath and friend of Parnell's) would not have had to disassociate himself following the scandal. Redmond would not have had to rebuild the IPP as a political force. Ulster opposition to Home Rule would probably still have surfaced (Ulster manufacturing had strong commercial ties with the British Empire) but might have been less violent and sectarian. Probably, as the unquestioned leader of an established party, Parnell wouldn't have caught a chill out campaigning in the wind and rain and might have lived a bit longer (though I think he had a diseased liver as well as pneumonia). Still, probably good for another six or seven years, say until 1900.