Kat has been away from Albert Square in recent months as she is looking after her dad Charlie, who suffered a stroke. In real life, Jessie Wallace - who plays Kat - has been on a break from the BBC soap.
EastEnders fans have seen Roxy Mitchell (Rita Simons) develop feelings for Alfie in Kat's absence, leading to speculation that there could be an infidelity storyline ahead.
Richie, speaking on The One Show, commented: "It's such a pleasure working with Rita. It's interesting about some of the publications - the ones that are interested in soaps - how they've said Alfie is going to go off with Roxy. But as soon as Alfie does that, he loses the moral high ground.
"But I had a meeting today, funnily enough, about future storylines - and they're going to be incredible. Because Jessie's back at work now after having a little break.
"I can only say, stuff that happened last year is nothing compared to what's going to happen over the next 12 months. It's going to be incredible."
Richie explained that he has adopted a different attitude towards EastEnders since returning to the programme in late 2010.
He said: "I genuinely do love it. I look forward to going to work, and probably more so because I had a long break from the show for five years. I did a few gameshows, I did some other dramas, I did some theatre.
"But coming back now, I've come back with a different attitude. I've got a young family, so I don't take it home with me and I don't take it as seriously.
"Because when I was first in the show, the whole Alfie thing blew up and it was incredible. It was wonderful to be part of that bubble, but after a while you step out of it and you see it for what it is. Now I'm a jobbing actor, that's what I do and that's how I pay the bills."
Richie is up for the 'Best Actor' prize at this year's British Soap Awards, which take place in London tomorrow (April 28).