Most of us won't get a peek inside the Olympic Park until 2012 (although they do host 'open days' and there will be test events before then - and have a gander at the webcams up here). Once a month, Diamond Geezer publishes a picture of the Stadium taken from the same spot, to show progress over time.
But you can also see quite a bit right now by just walking the canal which skirts the south perimeter of the Park, and jumping up onto a part of the Green Way which cuts right through it. Londonist went on this Blue Badge guided walk on a sunny cold January morning, which sets the whole project in the context of the local area. You can see some great industrial history, lots of disastrous 70s planning decisions, areas in dire need of change, and... the Big Breakfast House, lurking about 3 inches from the blue hoarding at the edge of the Park. Who knew?