changes to the Supplemental Index had unintended consequences which caused a shift from higher paying keywords to cheaper longtails. Google Instant is a fix but it doesn't mean that it will hurt the little guys.
The changes to the Supplemental Results resulted in Google "showing more by ensuring that every query is able to search the supplemental index". What Google Instant does is the recent Google Phrase Based Indexing and Retrieval Patent. Phrase based indexing is based upon clusters and phrases to display the order of the search result. The phrase based indexing system makes SEO more important and the content less so.