Here's a preview of the first, major aspect of 2015.
Mars in Aquarius opposes Jupiter Rx (at 21 degrees Leo) exact on January 1st. However, you'll probably start to feel this around December 28th or 29th. This is a zinger of an influence. Mars' action and initiative is pumped up by Jupiter (even though it's Rx) and Jupiter's push for more is triggered by Mars. Mars in Aquarius is rebel action, or the initiative that's detached from everything but the future. Jupiter in showy Leo is the Big Display. The tension of the opposition (actions versus belief, expansion versus aggression) cranks all this up to maximum.
Because Jupiter brings opportunity, there's potential for impulsive leaps (Mars) of faith (Jupiter) that land you in a sweet spot. Or carry you over the edge. There's a crusading feel to this one: charging ahead for what you think will benefit the greater good (Aquarius). And you can do a ton of good with this energy, as long as you don't fall victim to the Mars/Jupiter Shadow: self-righteous battles. In some ways, the power-hungry risk is even greater than a Mars/Pluto aspect, because Jupiter feels good. And when hyped up by Mars, it feels good to be aggressive.
You can see how that might benefit you, or trip you up.
21 degrees Aquarius and Leo in your chart is where you might be tempted to push, pummel or wave the flag. Stand up for what's right! Draw attention to the ____ and blow all the bad things out of the water! Jupiter is about philosophy, legal matters, and wisdom. So you can get swept up in the storm of fervent belief. Aquarius and Leo are Fixed signs, and Mars/Jupiter are both pushy and impatient. That's a potent combo of stubborn impulsiveness (if that makes sense). Make sure that you're charging in the right direction, because you can certainly make big changes in a short amount of time.
Jupiter Rx will be urging you to ask questions about what's been expanding in your life (all Rx transits are about re-evaluation) and Mars will give those questions an assertive edge. You'll want to know now. You'll want to make corrections, or dig deeper, or see the proof behind the promise...now.
Jupiter expands everything (the good, bad and ugly) so when Mars is added to the mix, there's a high risk of situations/conditions becoming inflamed. Since Jupiter is Rx, this will be a past or existing issue (not a new one).
You'll feel this opposition most strongly if you have natal/progressed planets, angles or Nodes from 18 to 22 degrees of the Fixed signs.
Tarot card in this post is from the Tarot Illuminati.