I asked Kinesis about this, because I think the Guest Exchange is very useful to have (I also use it a lot myself). It appears that fortunately this functionality is still present, but a bit hidden.This has been stripped down and there is no access to a peep of the Exchange for non-registered visitors.
Kinesis support guys gave me this instruction:
1) On main page, go to "Media"
2) Select either "Gold Price Chart" or "Silver Price Chart"
3) In the next screen select "exchange"
This takes you to the Guest Exchange



