Zoro will, indeed, get a new sword. It all has to do with Santoryuu … again, Zoro warned them of the difference between simply using three swords at once and practicing Santoryuu. Anyone with two arms and strong teeth and jaws could swing three swords around, but they'd probably end up hurting themselves ... Using one full size sword and what is effectively a dagger (the remains of Yubashiri) was not part of his style and would require making major revisions to his existing style. Not only would any new technique have to take the difference in blade length into account, but his existing moveset would have to be similarly revised ... Zoro needs a style which is as common as breathing to overcome all opposition, not a fledgling revision that requires attention best saved for his enemy. While Zoro might not simply discard Yubashiri, I am certain that he will replace it.
Meh – After having given it thought I'm leaning more towards this view now, too. The tipping point for me was the latest chapter, where we see Zoro fighting with Wado in his mouth. My idea of him adapting Santoryuu was entirely depandant on him putting Wado in his hand and Yubashiri in is mouth.
Your post also got me thinking about Wado more symbolically than I'd been thinking about it before. I think this was because I remembered that Zoro fought with Wado in his hands all through the Arlong arc, but forgot that this was only because he had no other swords to fight with at the time. As soon as he'd secured two other swords from Johnny and Yosaku, Wado was back in his mouth again, even though it was the superior fighting sword of the three.
So even though putting Yubashiri in his mouth would give Zoro less blade to move around (and this giving him a wider range of moves than when Wado was in his mouth), it would still be symbolically demoting Wado to a "fighting" sword, while elevating Yubashiri to a "symbolic" sword (the one carried into battle, but not fought with)
So when looked at in a symbolic context, there really is only one option left for Zoro : get a new sword. I suppose we could also say that "not fighting with a sword in the right hand" is an option too, since we've seen an example of it in the latest chapter -- but we know from what Zoro said back in Loguetown, that he doesn't really feel "secure" unless he's got three swords, and since we're just about to enter one of the wildest parts of the Grand Line, Zoro's got to feel secure, so that he can concentrate completely on his fighting.
So yes, new sword.
But NOT a gimmick one. No sea-stone, dial enhanced, logia, etc.
The only "gimmick" I'll accept willingly is a curse.
I think Zoro's thinking the same thing, too.
(if he wasn't he'd probably have kept the Vice Admiral's cutlass from EL, or taken Funkfried from the bridge, etc). He may be eager to get a new sword, but he dosen't seem desperate yet.