Since MetalArmor (Toph's Fanboy) is unable to get on the Wiki, he has given me some of his musings to post to the Wiki. Here is what he gave me, copied verbatim:
Suki was the way Bryke chose for the plot drew Sokka out of his depression and made him realize the world wasn't set against him finding hope in romantic love. No matter what Tokka fans may say about the matter, I will always agree with Sukkaneers that this is what Suki and Sokka's interactions during the "Secret of the Fire Nation" (in "The Serpent's Pass" part) were clearly meant to portray (unless, of course, Bryke clearly says something to the contrary, which I highly doubt will ever happen). From this understanding of the matter, the break-up of Sukka due to the strife of the War's aftermath would almost certainly only serve to make him more pessimistic and more cynical; the happy ending he was given with Suki at the end of the first series was clearly written to confirm Bryke's desire to overturn the possibility of Sokka retreating into himself and turning back to wallow in his depression once the War was over. To erase this line of development by snapping him and Suki apart during "The Promise Part 2", as Tokkaneers seem to want to happen to make their shipping possible, would only serve to erase the line of character development that Bryke very probably meant to be implied, and which Sukka shippers have a strong right to defend from being ignored or destroyed.
His bond with his younger friend also gives him hope, but in a different way. In that case, it is the hope in having her as a life-long friend, who may bear with him through any situation he gets himself into. In her case, it is hope that even if the world does reject him (or is highly likely to), he may find solace in one good friend. It is reasonably clear that this is what Toph and Sokka's heart-to-heart interaction during "The Runaway" (in which they speak about the damaged nature of both of their families) was meant to portray (it was the exact emotional effect it gave off to me upon watching it the first time), and this I take to be Bryke's intentions for the scene.
From this, I deduce that the "Tokka" interactions were included in the series as a fail-safe for Sokka, so that in case Sukka didn't work out Sokka could still go on without the world becoming unbearably bleak for him. If what I heard from an anonymous user about the Avatar artbook can be trusted (it does seem cohere well with the course the series took with Suki, in any case), Bryke said that they pretty much allowed Suki back into the series (being compelled into this by the fanbase popularity of the character) because they were interested see what would happen with Sokka and Suki's relationship during the natural progression of the story. Since Suki and Sokka were not predestined from the beginning by Bryke's preferences to end up happily ever after with each other like Katara and Aang always were, it seems likely that it would have been for this reason that they included the possibility of a "Tokka" relationship as a way to provide Sokka with some sense of hope in life in case they could not write Sukka as working out. If true, this would be why the theme of Tokka was first brought up in a noticeable fashion (by Bryke in the DVD commentary for that episode, during the scene implying her developing romantic jealousy toward Suki) around the same time Suki returned, and why it was played upon to the degree that it was during the first half of Season 3 (before Suki's return was set in stone, by the revelation that she was alive but imprisoned in "The Day of Black Sun, Part 2 - The Eclipse"). Toph was probably given her small crush on him to soften her up emotionally relative to him, but by the end of the series she almost certainly intended to give up acting on her crush in deference to supporting him platonically as a friend. (Saying this will not garner me any points from hardline Tokka shippers, I know.)
If Sokka and Suki are broken up in "The Promise", in all likelihood Bryke will have defended the shippings as they understood them while writing them, and will not let Gene Yang write anything contary to the manner in which the plot developed in the original series. Thus, if it is made necessary by a conflict of interests between Sokka and Suki's different political stances , the focus will likely be on the tragic circumstance which inflict this on his life and the solace he is able to find in his friends (particularly his closest friend, Toph), and not anything overtly romantic. To go much beyond this, I think, would be a unnecessary betrayal of a large segment of the fanbase; as much as I frequently get irritated with Sukka shippers for downplaying the platonic bond between Toph and Sokka to make their ship look absolute, they do protect key plot developments in Sokka's life which ought not be downplayed as well (and which I apologize for doing).
Regardless of their shipping preferences, I believe that the saner fans will ultimately be satisfied with the knowledge of the character's psychological well-being throughout life, no matter what context this ultimately takes. The [more rabid] ones, who ignore the priority of the plot over the shippings, we can do nothing about; if a necessary plot development shifts the line between the canon and noncanon relationships, some rabid shippers will be given more leeway for their actions and some others will be given less - but that is true even now, just with different segments of the fanbase.
...It's not 100% verbatim anymore, but I had to correct something that Plasma pointed out to me.