English spelling has changed historically, and it is not unreasonable to expect it to continue to do so in the future. Its future direction is difficult to predict, although, it's likely to include regularisation of irregular spellings and regularisation of irregular pronunciation (phonetic change). Spelling change generally is very slow, particularly for commonly used words, and increased use of print media acts to retard change.
English lacks a language academy to standardise spellings.
The pedagogic implications of spelling change are mostly found advanced levels, where studying an older text is appropriate, students may occasionally encounter archaic spellings (in addition to archaic words, and words that have semantically changed. Below advanced levels, since students are expected to adhere to standard English, spelling change, has little direct relevance to the ELT classroom. Teachers will be expected to teach English as it is used, so the students can use it.