Korea Herald quotes one ARM official for saying that Samsung will have a 64-bit in a new smartphone next year. Unfortunately, that doesn't really tell us much, because the question being replied to that would be "Who doesn't?".
The 64-bit chips were already planned for 2014 by almost all chip makers (even Nvidia actually, but theirs got pushed into 2015 because of further delays), so there's no surprise that 64-bit chips are coming even for Samsung's phones next year. The real question is when? That's because most of them are expected in the second half of 2014, so for example, it's almost inevitable that a Galaxy Note 4 would have it, but it's less certain whether Galaxy S5 would have it, especially if Samsung doesn't plan on using the stock ARM CPU's anymore, such as the 64-bit Cortex A57. Cortex A57 is also not planned to arrive until the second half of 2014 anyway, so it's less likely the Galaxy S5 would get it, even if Samsung wanted it.
There have been some rumors that is working on its own ARMv8-based 64-bit chip, but the rumors have been pretty vague, so we don't know exactly when to expect that. It is possible they would have it ready by the time Galaxy S5 comes to market, though, and therefore in it.
If that's their plan, then they will have their 64-bit chip ready even before Qualcomm, which probably won't have theirs ready until the second half of the year. That's actually a little surprising, because normally I would expect Qualcomm to take full advantage of the fact that they own an ARMv8 license and can build their custom CPU based on it at least 6 months before ARM's own CPU cores come out, even if theirs will be slightly less powerful (like Krait was vs Cortex A15).
There is one main reason why this may not have been possible this time around, and also why Apple managed to beat them to it. Qualcomm and everyone else is probably waiting to switch to the 20nm process node, too, as they go ARMv8. It's possible that because of that, they can't release them in the first half of 2014.
Qualcomm has to make its chips in TSMC's, Global Foundries', or Samsung's foundries. Samsung, on the other hand, can manufacture its own chips and it's possible they could make them a few months earlier, and they could also keep that process for themselves early on. That's why Samsung could be releasing a 64-bit chip (especially if custom) ahead of most others.
The ARM official apparently said that there will be a 128-bit processor in the next 2 years, too:
"As technology moves from, for example, shifting to face recognition on smartphones from the fingerprint scanner to unlock an iPhone, it requires more powerful memory capacity," he added.
However, it's unclear what he meant by that. Was he referring to 128-bit NEON instructions (which already exist in ARMv8), or 128-bit mobile GPU's (very likely, since we've had 64-bit ones for about a year). It's hard to imagine ARM would just move from ARMv8 to something like an ARMv9 just 2 years later (would make more sense 5 years later), so I'm skeptical he was referring to the CPU being 128-bit, especially since it would be much more efficient to do facial recognition with a co-processor/accelerator, than with the CPU itself.