In new Russian there are two competing spellings - бейл-аут and бейлаут. It is, I think, because, there are already two competing models. Time-out (or timeout, or time out) is given in dictionaries as тайм-аут. But similar Russian words, that were borrowed roughly at the same time, such as нокаут (knockout) and локаут (lockout) are spelled as one word, without the hyphen.
There are over a million references to бейл-аут on Russian Google, so it's fair to argue that the word is now part of the Russian language.
However, news reports on the Cyprus crisis and other items on the global financial tremors struggle to use пакет мер по спасению (rescue package), спасение (rescue), помощь (help), выручка (rescue) as substitutes for the hard-hitting bail-out. But Russia doesn't seem to offer anything as short and hard-hitting as the бейл-аут. In fact, I myself have just contributed to the proliferation of this new word by using it in my short blog-post 'Cyprus: the End of Europe' on BFM.ru.
And there is another consideration against writing бейлаут as one word — the proclivity of Muscovites to shift stresses to accommodate a natural inclination for an ultimate, or, in longer words, a penultimate stress. Маркетинг that popped up in the 90s is often pronounced as маркéтинг in Russian. What if бейлаут becomes бейла´yт? On the model of the fairly obscure but known арна´ут (a historical ethnonym for an Albanian)? God forbid!