What does the European Commission’s antitrust ruling mean for Google Shopping?

On 27th June, Google was fined £2.1bn by the European Commission for breaching antitrust rules by promoting Google Shopping's comparison service at the top of the SERP. With only 90 days to comply with the ruling, what’s in store for advertisers?
What happened?
The European Commission has ruled that Google abused its dominant position in the search engine market and gave an illegal advantage to another Google product, its own comparison shopping service. Initially launched as Froogle