Victory over Germany opens up many possibilities

Ireland are tied on points with Poland, both teams meeting in Poland in the last match. 

This leaves Ireland with the following options:

Beat Poland or a high score draw

The easy way to qualify now is simply beat Poland or a 2-2 draw or higher. If the teams are level on points then it will go to head to head. Both teams drew 1-1 in Dublin already - so a 2-2 draw or higher would put Ireland through on away goals. Even in the case of a three way tie (if Germany lose against Georgia) 2-2 (or any draw in fact) would be enough for Ireland to qualify in 2nd based on the matches involving the three nations.

A no score/low score draw

A nil-nil would almost certainly mean Poland would be 2nd on the away goal they scored in Dublin. A one-one should put them second based on goal difference. So Ireland would likely be 3rd with a no score/low score draw. The one exception would be if Germany are beaten by Georgia then a three way tie would put Ireland ahead of Poland and actually in 1st and automatic qualification (I think Poland and Ireland qualify in that case, with Germany third after only beating Poland once of the top teams and one draw against Ireland). 

But realistically a no score/low score draw would see Ireland go into a play-off against the other third placed teams - seeded based on UEFA co-efficients. A draw would give Ireland 27322 coefficient points. This would be enough to rank ahead of Israel, Slovenia, Turkey, Norway (assuming they don't beat Italy) and both Albania or Denmark.

In that case I cannot see Ireland not being seeded for the draw and avoiding Ukraine, Sweden or Netherlands (if they can overhaul Turkey for 3rd in Group A).

If Norway do beat Italy though then Croatia are in the playoffs instead of Norway and Ireland will not be seeded ahead of Croatia. It would then become very important that Turkey hold off Netherlands.

Defeat :(

If Ireland lose to Poland they are obviously still in the play-offs. It would make seeding more difficult though. A defeat would give them in the region of 26902. This opens the door for Turkey to out rank Ireland, Turkey have a potential 27013 coefficient points. Denmark with 27090 coefficient points would just edge ahead of us for seeding. So in this case Ireland may only be seeded ahead of Israel, Slovenia and Norway (assuming again they don't beat Italy). This wouldn't be good enough to be top seed and would mean a play-off against one of Turkey/Netherlands, Ukraine/Hungary, Sweden or Denmark.

To avoid this we need Turkey to slip up against Iceland[H] or Czech[A] but not so bad that it lets Netherlands back up to 3rd. Or we need Albania to fail to beat Armenia.  A win would put Albania out of 3rd and in to 2nd with Denmark replacing them in 3rd. In this scenario where Ireland lose then Denmark would be ranked ahead. Armenia are bottom of the group with only 2 points - but those draws came against Serbia and Denmark and all their defeats but one were by single goals. So it's certainly within their reach to draw with Albania and keep them in 3rd.

Matches to watch.

Poland vs Ireland - Ireland have their destination in their own hands with this.

Ukraine vs Spain - A win for Ukraine would put them top placed 3rd place and they would qualify automatically. In a play-off situation Hungary might be a better option than Ukraine. Hungary and Ukraine are at the moment top 2 in the 3rd placed teams.

Armenia vs Albania - Albania are 1 point behind Denmark, but Ireland want Albania to stay in 3rd because of their much inferior UEFA co-efficient which may affect the seedings. A draw here for Albania wouldn't be enough to topple Denmark as Denmark would hold 2nd on head to head results. So anything but a win for Albania would suit Ireland.

Turkey vs Czech and Iceland vs Turkey - Turkey have a better head to head than Netherlands so a win and a draw would guarantee they hold onto 3rd place. But anything better than a win and a draw will give them enough coefficient points to threaten Ireland's seeding. So Ireland are hoping for exactly one win and one draw from these games for Turkey.

Italy vs Norway - If Norway lose or draw it opens the door for Croatia to drop them into 3rd place in the group. It also opens the door for Ireland to jump them in the UEFA coefficient system. This would help Ireland to be seeded because we may be seeded ahead of Norway, but no chance of being seeded ahead of Croatia.

Croatia vs Bulgaria and Malta vs Croatia - Two wins here for Croatia would help them crawl out of 3rd spot if Norway slip up as hoped.

Israel vs Belgium - Israel (3rd in Group B) have two points on Bosnia (in 4th). Assuming they win against Cyprus then a draw against Belgium could see Israel hold on to 3rd. Israel would not be seeded ahead of Ireland, Bosnia would be. Bosnia have Wales[H] and Cyprus[A] left to play.