Here are the most notable changes affecting business travellers:

London – Paris:

First train will depart at 0540 instead of 0525, Monday-Friday

Two morning trains are now non-stop services: 0701 and 0831

0730 departure is now only on a Monday

Paris – London

An additional peak afternoon train departs 1743 Tuesday to Friday

London – Brussels

Timetable changes to enhance connections to Amsterdam

All trains will now stop in Lille

Eurostar Booking Tips

There are a few simple tips to finding availability and the best prices in my article here