A pleasant, relatively gentle loop with views of the Musical Bumps and beyond. I wasn't sure what to expect since the trails on Blackcomb aren't as well known or well publicized as those on Whistler, but I found it to be a good hike that's well-matched to the time available at this time of year. Note that the return leg has a good stretch of uphill - about 150 m of the climb is on the return. The trail is rocky in places so might not be as easy for beginner hikers as the green/blue symbols on the map may suggest. Expect to see marmots :-)
Currently, the Blackcomb chair lifts are not in service so getting to Blackcomb requires taking the Whistler Village gondola and then the Peak 2 Peak. Hardly onerous :-) Pick up the Alpine trail map as you get on the gondola. From the Blackcomb station, the trail heads off along the flanks of Blackcomb Mountain. The meadows are now well-past it of course, but the views remain excellent. I suspect that the meadows would be fantastic in July and August. Blackcomb Lake is nothing special but has a couple of nice benches to sit and enjoy the view. Decker Tarn is much prettier, if smaller, and appears to contain glacial meltwater (from an unseen glacier) on account of its colour.
The Overlord Summit viewpoint (a shoulder, not a summit) offers superb views of the Musical Bumps, Overlord, its glacier and Fissile, Castle Towers and the Cheakamus glacier and Black Tusk (with the Tantalus Range over its shoulder). Mt Garibaldi is barely visible as a bump on the Castle Towers ridge, and the Table is visible for some of the route. Of course, to the west is Mt Fee (with the triangular Ashlu behind it), Pyroclastic and Cayley, Brandywine and Powder Mountain; Rainbow and beyond and north to Ipsoot and the south face of Mt Currie. Not a bad collection of peaks :-)
This route is exactly the same as described in the Copelands' (now out-of-print) book Don't Waste Your TIme in the Coast Mountains, although some of the trails have different names. It is also the approach to ascending Decker Mountain, which looks very straightforward.