No idea, I haven't heard anything about a new version, I can't find any information on it anywhere.
Anyway, one of the best new features in this game I think is the way you can see the route your ghost is taking in Time Trial, it makes it much easier to improve on your previous time, and i've been having lots of fun getting better times. Is anyone willing to challenge my Time Trial times?
Track / Best Time / Best Lap
Figure-8 Circuit - 1:25:540 - 0:27:533
Yoshi Falls - 0:54:528 - 0:17:921
Cheep Cheep Beach - 1:39:044 - 0:32:507
Luigi's Mansion - 1:54:364 - 0:36:193
Desert Hills - 1:29:939 - 0:28:794
Delfino Square - 1:48:218 - 0:35:816
Waluigi Pinball - 2:17:205 - 0:45:455
Shroom Ridge - 1:56:863 - 0:37:622
DK Pass - 2:06:578 - 0:40:549
Tick Tock Clock - 1:52:481 - 0:35:946
Mario Circuit - 1:47:909 - 0:35:391
Airship Fortress - 1:58:463 - 0:38:458
Wario Stadium - 2:10:410 - 0:42:974
Peach Gardens - 1:44:738 - 0:33:011
Bowser Castle - 2:18:539 - 0:45:790
Rainbow Road - 2:14:188 - 0:43:909
SNES Mario Circuit 1 - 0:47:760 - 0:15:455
N64 Moo Moo Farm - 1:15:441 - 0:24:667
GBA Peach Circuit - 1:04:416 - 0:20:999
GCN Luigi Circuit - 1:22:544 - 0:27:330
SNES Donut Plains 1 - 1:05:836 - 0:21:157
N64 Frappe Snowland - 2:01:259 - 0:39:938
GBA Bowser Castle 2 - 1:46:581 - 0:34:597
GCN Baby Park - 0:47:483 - 0:09:157
SNES Koopa Beach 2 - 0:50:275 - 0:16:480
N64 Choco Mountain - 2:04:602 - 0:40:936
GBA Luigi Circuit - 1:41:377 - 0:33:132
GCN Mushroom Bridge - 1:27:154 - 0:29:006
SNES Choco Island 2 - 1:01:156 - 0:19:962
N64 Banshee Boardwalk - 2:13:502 - 0:43:860
GBA Sky Garden - 1:35:170 - 0:30:294
GCN Yoshi Circuit - 1:42:581 - 0:33:949