If we remove all our gear, we can see our Power Pips chance baseline in the stats of our wizards. It's probably just an oversight, but now that we can see our Shadow Pips chance in our stats, it's odd that there isn't the baseline. I've read here and there that we get a 20% baseline when we learn our first Shadow spell but it would be nice to actually see it ingame as we do with Power Pips. Especially now with the new Shadow Pips bonus from Darkmoor gear and if, like Power Pips, the chance baseline increases for Shadow Pips too with level in the future updates.
If you look closely, you will see that the section says "Shadow Pip Bonus". I agree though, it would be nice to see our total Shadow Pip chance instead of just the bonus from gear.