Just to clear up a few things: ILE was abolished from January 2007, when the Life in the UK test was introduced. What you have to do if your relationship outside the UK has persisted for 4 years is to apply for a regular spousal visa, but ask for it to be endorsed with "Knowledge of Life in the UK required". Upon passing the test you could then apply for ILR.

Since those over 65 or severely disabled (e.g. blind, paraplegic, no hands) were exempt from the LIUK test, it would be silly to give them a visa and then make them apply for ILR after entering the UK. Well, not silly for the Home Office which got hundreds of pounds extra in fees. But anyway once this was pointed out by some immigration lawyers (who the Home Office actually used to listen to), they restored ILE for anyone who had taken the test and returned home, or was exempt.

So then people started entering the UK as tourists to take the test, and returned home to apply for ILE. The UKBA (as it became known) didn't like that and denied a few people at the border if they were dumb enough to tell the officer that it was the purpose of their visit. Later they ruled it out completely by requiring proof of UK address to take the test.

Anyone applying with a >4 year relationship has until July 6th to request this "provisional ILE". As visas can be post-dated by 3 months, they would have 30 months to enter the UK, get a bank statement and take the test, and get ILR under the current rules.

The people affected by this specific change are those who have been married between 2 to 4 years, who were waiting to qualify for provisional ILE, and now have to bring their move to the UK forward or be subject to the 5 year probationary period.

The problem they are trying to solve here could also be fixed by giving benefits to citizens only as opposed to all ILE/ILR holders. My aunt receives benefits but refuses to get British citizenship because it would mean giving up her original citizenship, which gives benefits to all citizens. I don't see why she should benefit from both systems when she only lives in one country. But many countries also give full access to welfare for all permanent residents, and it is probably easier for the government to abolish instant ILE/ILR than reform the entire welfare system.