Why the fanfare? Because having been asked over the years why anyone would bother voting for them in a General Election they can't possibly win, Plaid and their friends north of the border find an answer this time round. Neither Alex Salmond nor Ieuan Wyn Jones can walk into Downing Street when all the votes are counted but in a hung parliament, they could pocket big concessions for Scotland and for Wales.
Bingo: a weak position turned into a coherent one, even one of relative strength argue Plaid.
A "pathetic" attempt to disguise their irrelevance, say the other parties.
Snazzy title? This being Plaid, then yes of course. "4 Wales, 4 Scotland" is the agreement signed in Westminster this morning. Colleagues up in Glasgow tell me Wales gets the first mention in the flyer they were sent too just in case you were wondering how these niceties work.
The pledges read like this: fair funding for Wales and Scotland, protecting local services and the most vulnerable, action to help the green economy and support for business growth.
The other detail, that neither Plaid nor the SNP would enter into a formal coalition. Their hope is, clearly, that they will be called upon to offer their support on a vote by vote basis. In other words if the maths dictates that that you really need our support in a vote of no confidendence, or to get your budget throught, you'll have it ... as long as we get something in return. In crude terms they've calculated that it's more profitable to work on an a la carte basis and surely a much easier political sell to their own party. Close but not too close.
Practical, grown-up politics, say Plaid.
A "sad spectacle" of a party clinging desperately to the coat-tails of the SNP, say Labour whose response is particularly vitriolic.
Note the interesting use language too. Plaid are not talking about a parliament that is 'hung', rather one that is 'balanced'. Why, I heard the party's Director of Elections Helen Mary Jones asking the other day, is the language surrounding agreements between parties so macho and unpleasant? It's all about 'getting into bed with' or 'cosying up to' another, larger party. A 'hung' parliament sounds stymied, hamstrung, not able to get on with anything. A 'balanced' one sounds quite different.
The other major parties have come up with choice words of their own: "a joke", "deluded", "separatist" to name a few.
Will either Gordon Brown or David Cameron come knocking? Haven't there been signs that Mr Cameron, in particular, would rather look to parties in Northern Ireland, or, of course, to a deal with the Lib Dems?
Remind me to buy new batteries for the office calculator.