Thus far, teams are generally opting instead for a diverse but necessarily small pool of variations on the required 2/4 tempo and accompanying permitted rhythm (waltz, march, or more polka). Traditional ballroom, Country-Western, classic musical, and French themes are so far the most popular, and will be explored here in weeks to come, as enough videos of these programs in competition actually become available. For the moment, let's focus on the polka -- Yankee and floor -- itself.
The Yankee Polka pattern is a bit of an outlier for having originated in the U.S., and as (comparatively) recently as 1969, in an apparently polka-friendly period in American culture. As with the blues, Ice-Dance.com provides an excellent reference page outlining the pattern's steps and technical requirements. But also of note is what else separates the Yankee Polka from a pattern like blues or last year's rhumba, and that's a sense of continuity with its source material.
Analyzing a step chart from the polka isn't especially instructive on a technical level, but knowing what most characterizes the style -- the hop or half-step -- is key. A little historical background on this dance is also useful, and this not-historical video gives some idea of how the dance style initially fit within a ballroom context:
Today the style is considered far more as a cultural dance, with Polish and German styles among other variants. This instruction video, however, strips it down to pure technique, which may be more helpful here:
The ISU's Yankee Polka guidelines assert that The character of the dance is achieved through the interesting use of one beat edges and very short steps skated on the "and" between counts. In this well-skated and rather unusual take from Isabelle Delobel and Olivier Schoenfelder, we can see two "very short steps" in the first two steps of the compulsory dance proper (beginning at 0:30), followed by a three-turn recalling the dance's contrasting longer steps:
Of course, of almost as great importance to a properly-rendered on-ice polka is the dance's character. The steps give an indication, but the attitude needs to be more full-bodied: the polka and Yankee Polka are sprightly, happy, upbeat dances. A skater may seek out darker-edged 2/4 musical selection, and may be successful in such a search -- but a mournful or angry performance seems unlikely, if not costly. The tempo lends itself to a bouncy character; the required steps reinforce the tempo; the full dance cannot clash in spirit without a team's anticipating some confused feedback.
To conclude, I'll leave you with an überconventional -- and quite appropriately bouncy -- take from former German champions Kati Winkler and René Lohse as a balance for all those untraditional variations on the polka to come,: