On today's page, he'll discover a tiny Kenny face drawn on Rat's coffee mug with the note "There, I drew Kenny". On Monday, I think he'll love the vandalism on his calendar.
Lately, I've started FINALLY watching Dr. Who, so his challenge to draw something Dr. Who related was actually a great idea. I'm only to season 2, episode 2 of the new series, so PLEASE no spoilers. I actually made the mistake of looking up the graffiti on the TARDIS, expecting a behind-the-scenes reference, but apparently spoilers travel back in time. I already knew a lot about Dr. Who before watching it, enough that I could pass as a Whovian, but thankfully I'm still being surprised by things in the show.
I expect to be caught up with the entire new series before this year's Christmas episode.
"He's not MY Doctor", heh. So who's "my" Doctor? Before starting, I expected it to be David Tennant. Since I've only seen 2 David Tennant episodes(not including when he regenerated, short appearance), that expectation hasn't changed, but I'm definitely liking him. He was the first Doctor I started seeing a lot of, so he's who I think of when I think of the Doctor. Now, when I catch up and start watching CLASSIC Who... I expect Tom Baker to be stiff competition for "my" Doctor.

As for the "Apple Keynote" note... my co-worker's using a Mac Mini from 2012. Since the last Mac Mini was from 2014, he really wants to wait for the next model. Apple doesn't usually announce hardware at the keynote in June, but they sometimes do. They'd BETTER announce some new desktop computers really soon! The latest Mac Pro is slower than the iMac in most tests.

I also get some joy in drawing Dr. Who fanart on the page for the Queen's Birthday, for the extra Britishness.