I think it's fine- when you look up the statistics page, it actually does list digital separately in the breakdown. I've never put too much stock into the general 'total' number of items anyway- there's a big difference between having 500 items that are all games, and having 1000 items, but 600 of that is old magazines and strategy guides, y'know?
I usually only give the 'games' number when people ask how big my collection is anyway, since one would assume systems, controllers, & tat are going to be present anyway. Just like if you told someone you have 1,000 DVDs, they'll assume you have a player somewhere too.