To be honest, my first reaction upon seeing Shovel Knight in the character parade trailer was negative. But the moment I heard his gobbledygook speech while he's saying he embarked on such a grand adventure that he ended up in the wrong game, brought a smile to my face. So, I can sympathize with the people who greatly took offense of a non-Playtonic/Rare character making a guest appearance in Yooka-Laylee. That being said we could have predicted that Playtonic Games would make a decision like this, since they have said in the past their Playtonic Universe is taking cues from the Marvel Universe - where characters that hail from other universes sometimes pay a visit to the Marvel Universe.
I would like to see that Playtonic Games do something creative with Shovel Knight's cameo in Yooka-Laylee, instead of only helping him with a task and giving you a pagie before he departs to his own universe. We have never seen what is behind Shovel Knight's suit of armor, this would be a perfect opportunity for Playtonic to implement a twist that would surprise the player. For example:
After helping Shovel Knight in finding a treasure chest filled to the brim with gold, he rewards your kindness by giving you a good whack of his mighty shovel! Which an angry Laylee responds to with "Hey! What's that for? Tin head!" Shovel Knight laughs at the duo as he takes off his helmet, underneath it is... a blue minion? Yes! It's the talkative blue minion (from the recent EGX footage) who Yooka and Laylee spoke to earlier, turns out he's a spy working for Capital B. "I guess you can judge a book by its cover," says Laylee upon seeing the blue minion's not so handsome face. The Imposter Knight™ mocks Yooka and Laylee for believing his lies and teleports away with the treasure, leaving them in the cold with nothing to show for all of their hard efforts. Luckily, later in the game you can find this unique blue minion in Hivory Towers and return the favor by smashing his head flatter than a pancake with his own shovel, while you reclaim the booty.
The last time Rareware ever made a twist like that was in Jet Force Gemini at the very end of the game. It would be hilarious if Playtonic Games also include a similar twist in one of their games.