Edit for some further thoughts: I could see this play out several different ways. Dems could potentially stall on the nomination, to maximize the "gamesmanship" rhetoric leverage of any Republican opposition to the nomination. But if the nominee were confirmed by June, the whole thing might be largely forgotten by the election in November. So potentially, we could see a very quick confirmation. This definitely is a massive boon to the Democratic party; they've just been handed a wildcard and have every ability to choose exactly how to play it.
I'm no fan of dehumanizing death, but Scalia's death will have enormous ramifications. Keep in mind:
1. Burwell v Hobby Lobby (private corporate responsibility for birth control re: Obamacare) was 5-4
2. Legal pragmatism arguments against criminal justice matters under equal protections grounds have already been very close to succeeding (or actually have). Could mean the end of the death penalty in the US.
3. Scalia opposed Guantanamo inmates' ability to challenge their detention in US Courts in the Boumediene v Bush decision
4. Scalia consistently opposed expansion of national healthcare
5. Citizens United was 5-4 with Scalia supporting the decision (this is what created superPACs), so potentially this could result in a limitation of corporate personhood
6. Potential liberalization and modernization of intellectual property rules, particularly in context of software (see: denial of certiorari of https://en.wikipedia.org/wiki/Oracle_America,_Inc._v._Google...)
Further edit: SCOTUSblog analysis on the political situation: http://www.scotusblog.com/2016/02/first-reactions-on-the-pas...