Brexit is supposed to happen now. No one has any idea how to implement it, leaving the default option of a no-deal crash-out. Fortunately, the EU have granted an extension: the new crash-out date is the 12th of April, with a further extension to the 22nd of May if a deal is reached.
It’s extraordinarily unlikely that the current deal will be affirmed. It has already been thrice defeated (divisions 293, 354, and 395) in some of the worst government defeats in Parliamentary history, even after Theresa May offered her resignation in an attempt to get it through. There is also very little that can be done to amend it without EU renegotiation (nor is there much more that can be done with EU renegotiation, given the combined requirements for a deal set by Theresa May and the EU, but given that, the EU are not amenable to renegotiation anyway), and Parliamentary rules prohibit multiple votes on the same substantial question (656 Commons Hansard 775).
Of course, the simplest thing to do — at least procedurally — is simply crash out in two weeks, since doing so merely requires that nothing be done. This option was rejected (divisions 357 and 359), but without Parliament actually affirming an alternative, it remains the automatic result. The consequences of doing this, however, would be incredibly painful for the UK. Crashing out is the “plan” of disaster capitalists and the clueless. The other unilateral option the UK has is to revoke Article 50.
Other plans require EU coöperation, given the length of time they would take, but the EU have indicated their willingness to grant a further extension for them. The simplest is for the UK to hold a second referendum. This time, instead of Cameron’s plan of fucking a pig, then fucking the country, then fucking off, with a “simple in-or-out choice”, the country could know what the options really are: the negotiated deal, no deal, or remain. Alternatively, a new general election could be held, with detailed Brexit plans (potentially including “don’t”) in every party’s manifesto, and May’s agreement that, in the event that the Tories win a majority or coalition government, she will give up her position. This would allow for a new negotiator, with different priorities, to begin a new negotiation with the EU. However, such a plan would almost certainly be opposed by the DUP, by TIG, and by many Tories. Either of these options, given the requirement for a further extension, would also require the UK to participate in EU elections. As the EU have already planned for elections that do not include the UK, a request to revert those plans would need to be made with sufficient time.
While almost no one wants to crash out, thus far, it seems no one is willing to prevent it, either. While any Brexit would surely be temporary, a no-deal Brexit — as the most painful option — would likely be the shortest. Ironically, the most hardcore Brexiteers may well get their wish of ending the relationship with the EU in the short term, but in doing so, they make Britain’s return to the EU that much more certain, and in returning, Britain would almost certainly lose the many special benefits it has now, and instead be obligated to participate in the “ever closer union”.