Yeah, this is definintely a good thing for Smackdown. While I think the way they put they did the title switch was crap booking, i think that Nexus appearing on both shows will be a good thing, if it happens.
The Nexus, since their debut, have been the best act on WWE television. While some may argue that we've already been oversaturated with Nexus, id argue that we've been oversaturated with Wade Barrett, although I do think he's been outstanding. This will give Slater and Gabriel a chance to shine, and in a sense, step out of the shadow of Wade Barrett. It will definitely be sink or swim time for them, and I think they'll pass, as both are quick and athletic, as is the majority of the Smackdown roster.
However, my fear is that since WWE has so de-emphasized tag team wrestling, we may never see them on Smackdown. The Hart Dynasty were champs for 5 months, and they made exactly one appearance on Smackdown, which only served the purpose of having them lose to the team that would take the belts from them. So Im not going to say it's a given Nexus will appear on Smackdown much, but if they do, it will be a good thing, and hopefully give Gabriel and Slater a chance to show what they can do.