Sure there is, the comma placement makes it appear that "today" is the day the prophecy would be fulfilled.
Moving the comma after "today" makes it clear that Jesus is speaking about the date of the pronouncement instead of the date of the fulfillment.
The reason that it would appears to have a different meaning is because of a deficiency in the grammar of most English speakers. I say this acknowledging that I didn't understand the grammar of "shall' and "will" myself until I learned it from reading biblical grammar. It "dawned" and then I afterwards found confirmation through actual grammar authorities, including Wikipedia and "The King's English."
The reason why changing a comma placement is unjustified is because Jesus that is not an accurate translation of the phrasing. Many many times in the gospels Jesus says "Verily I say unto thee, ..." and that phrase requires a comma.
Luke 18:29 KJV
(29) And he said unto them,
Verily I say unto you, There is no man that hath left house, or parents, or brethren, or wife, or children, for the kingdom of God's sake,
Luke 21:32 KJV
(32)
Verily I say unto you, This generation shall not pass away, till all be fulfilled.
Luke 23:43 KJV
(43) And Jesus said unto him,
Verily I say unto thee, To day shalt thou be with me in paradise.
There is no reason that Jesus would suddenly change from this pattern in this one and only instance, and changing the location of the punctuation would not be a properly accurate translation. And I'll say this also, one should NEVER start altering the bible text to make it "say what it should have said." That is a dangerous slippery slope.
Regardless, the context of the passage "When you come into your kingdom" combined with the actual grammar of the passage "Today shalt" (the command is proclaimed that day) doesn't require editing the text. Those that believe the bible (including Christ's words to the Sadducee) already have had it iterated dozens of times that the dead await the resurrection without knowledge and in silence, and that there is no life without benefit of that resurrection.
If someone is determined to twist a scripture backwards and make it contradict the rest of the bible, such will always find a way. Changing the text to make it appear to say what you want or arguing against the translation is not a legitimate method. Stay true and simply insist that the scripture be read properly as it is already written, and let those that refuse to accept the scripture as it is written be in the wrong.